chore: 1.5.0

KDE's own middle-click paste is turned off along with everything else. Inside a
Chromium application the flag already settles it - with autoscroll on, Blink
stops pasting the primary selection - but everywhere else on the desktop middle
click goes on pasting, which is the thing this program exists to get away from.

KWin has a switch for it on a Wayland session, where the paste is a protocol
the compositor either offers or does not, and that is what gets written. It is
true from the next login on. What the key said before is recorded, so disable
puts it back, and a key that already said no is left alone and never switched
back on. X11 has no such switch and nothing is written there.

Off under Settings for anyone who wants the paste kept.

.github/workflows/check.yml

@@ -0,0 +1,28 @@
+name: check
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  check:
+    name: syntax and shellcheck
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      # The Makefile skips whatever is missing rather than failing, so the
+      # tools it looks for have to be here or the check checks less than it
+      # appears to.
+      - name: Install the tools the Makefile looks for
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y --no-install-recommends \
+            shellcheck gettext scdoc
+
+      - run: make check
+
+      - name: Build the catalogs and the man page
+        run: make build

.github/workflows/release.yml

@@ -0,0 +1,256 @@
+name: release
+
+on:
+  push:
+    tags: ['v*']
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: >-
+          Build the repositories with a throwaway key and install from them,
+          without publishing anything. This is how the release path gets
+          exercised without cutting a tag.
+        type: boolean
+        default: false
+
+permissions:
+  contents: write
+
+jobs:
+  deb:
+    name: Debian package
+    runs-on: ubuntu-latest
+    container: debian:stable
+    steps:
+      - name: Install the build tools
+        run: |
+          apt-get update -qq
+          apt-get install -y --no-install-recommends \
+            ca-certificates git make gettext scdoc dpkg-dev
+
+      - uses: actions/checkout@v7
+
+      - name: Check the tag against the Makefile
+        run: packaging/check-version.sh "${{ github.ref_name }}"
+
+      - run: packaging/build-deb.sh
+
+      - name: Look inside what was built
+        run: |
+          dpkg-deb --info dist/*.deb
+          dpkg-deb --contents dist/*.deb
+
+      - uses: actions/upload-artifact@v7
+        with:
+          name: deb
+          path: dist/*.deb
+          if-no-files-found: error
+
+  rpm:
+    name: RPM package
+    runs-on: ubuntu-latest
+    container: fedora:latest
+    steps:
+      - name: Install the build tools
+        run: |
+          dnf install -y --setopt=install_weak_deps=False \
+            git make gettext scdoc tar rpm-build rpm-sign systemd-rpm-macros
+
+      - uses: actions/checkout@v7
+
+      - name: Check the tag against the Makefile
+        run: packaging/check-version.sh "${{ github.ref_name }}"
+
+      - run: packaging/build-rpm.sh
+
+      # Signed here rather than alongside the APT repository, because this is
+      # the one place with a native rpm-sign. A dry run signs with a key it
+      # makes on the spot, so the command itself is still exercised.
+      - name: Sign the package
+        env:
+          GPG_PRIVATE_KEY: ${{ secrets.GPG_PRIVATE_KEY }}
+          DRY_RUN: ${{ inputs.dry_run }}
+        run: |
+          if [ "$DRY_RUN" = "true" ]; then
+            gpg --batch --passphrase '' --quick-generate-key \
+              'dry run <dry-run@example.invalid>' rsa2048 sign never
+          elif [ -n "${GPG_PRIVATE_KEY:-}" ]; then
+            printf '%s' "$GPG_PRIVATE_KEY" | gpg --batch --import
+          else
+            echo "No GPG_PRIVATE_KEY secret; leaving the package unsigned."
+            exit 0
+          fi
+          keyid="$(gpg --list-secret-keys --with-colons | awk -F: '/^sec:/ { print $5; exit }')"
+          rpmsign --define "_gpg_name $keyid" --addsign dist/*.rpm
+          gpg --armor --export "$keyid" > dist/rpm-signer.asc
+          rpm --import dist/rpm-signer.asc
+          rpm --checksig dist/*.rpm
+
+      - name: Look inside what was built
+        run: |
+          rpm -qip dist/*.rpm
+          rpm -qlp dist/*.rpm
+
+      - uses: actions/upload-artifact@v7
+        with:
+          name: rpm
+          path: |
+            dist/*.rpm
+            dist/rpm-signer.asc
+          if-no-files-found: error
+
+  publish:
+    name: Release and repositories
+    needs: [deb, rpm]
+    if: startsWith(github.ref, 'refs/tags/v') || inputs.dry_run
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/download-artifact@v8
+        with:
+          path: incoming
+          merge-multiple: true
+
+      - name: Attach the packages to the release
+        if: ${{ !inputs.dry_run }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh release create "${{ github.ref_name }}" \
+            --title "${{ github.ref_name }}" \
+            --generate-notes \
+            incoming/*.deb incoming/*.rpm \
+          || gh release upload "${{ github.ref_name }}" \
+            incoming/*.deb incoming/*.rpm --clobber
+
+      - name: Install the repository tools
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y --no-install-recommends \
+            dpkg-dev apt-utils createrepo-c
+
+      - name: Get a signing key
+        id: key
+        env:
+          GPG_PRIVATE_KEY: ${{ secrets.GPG_PRIVATE_KEY }}
+          DRY_RUN: ${{ inputs.dry_run }}
+        run: |
+          if [ "$DRY_RUN" = "true" ]; then
+            gpg --batch --passphrase '' --quick-generate-key \
+              'dry run <dry-run@example.invalid>' rsa2048 sign never
+          elif [ -n "${GPG_PRIVATE_KEY:-}" ]; then
+            printf '%s' "$GPG_PRIVATE_KEY" | gpg --batch --import
+          else
+            echo "present=no" >> "$GITHUB_OUTPUT"
+            echo "::warning::No GPG_PRIVATE_KEY secret - the apt and dnf repositories were not updated. The packages are on the release."
+            exit 0
+          fi
+          echo "present=yes" >> "$GITHUB_OUTPUT"
+
+      - name: Check out the published repositories
+        if: steps.key.outputs.present == 'yes' && !inputs.dry_run
+        uses: actions/checkout@v7
+        with:
+          ref: gh-pages
+          path: pages
+        continue-on-error: true
+
+      - name: Update the repositories
+        if: steps.key.outputs.present == 'yes'
+        run: |
+          # First release, or a dry run: there is no branch to start from.
+          if [ ! -d pages/.git ]; then
+            rm -rf pages && mkdir pages
+            git -C pages init -q -b gh-pages
+            git -C pages remote add origin "https://github.com/${{ github.repository }}.git"
+          fi
+          rm -f incoming/rpm-signer.asc
+          packaging/publish-repos.sh pages incoming
+
+      - name: Check that what was written can be verified
+        if: steps.key.outputs.present == 'yes'
+        run: |
+          find pages -type f -not -path '*/.git/*' | sort
+          echo '--- Release ---'; cat pages/deb/Release
+          echo '--- Packages ---'; cat pages/deb/Packages
+          gpg --verify pages/deb/InRelease
+          gpg --verify pages/deb/Release.gpg pages/deb/Release
+          gpg --verify pages/rpm/repodata/repomd.xml.asc pages/rpm/repodata/repomd.xml
+
+      # The proof that the repository works is apt reading it: the signature,
+      # the index, the dependencies and the program that comes out the far end.
+      - name: Install from the repository that was just built
+        if: inputs.dry_run
+        run: |
+          sudo install -d -m 0755 /etc/apt/keyrings
+          sudo gpg --dearmor -o /etc/apt/keyrings/middleclick-autoscroll.gpg < pages/KEY.gpg
+          echo "deb [signed-by=/etc/apt/keyrings/middleclick-autoscroll.gpg] file://$PWD/pages/deb ./" \
+            | sudo tee /etc/apt/sources.list.d/middleclick-autoscroll.list
+          sudo apt-get update
+          sudo apt-get install -y middleclick-autoscroll
+          middleclick-autoscroll --version
+          middleclick-autoscroll list
+
+      - uses: actions/upload-artifact@v7
+        if: inputs.dry_run
+        with:
+          name: pages
+          path: pages
+          include-hidden-files: true
+
+      - name: Push them
+        if: steps.key.outputs.present == 'yes' && !inputs.dry_run
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          cd pages
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add -A
+          git diff --quiet --cached && { echo "nothing changed"; exit 0; }
+          git commit -q -m "Publish ${{ github.ref_name }}"
+          git push "https://x-access-token:${GH_TOKEN}@github.com/${{ github.repository }}.git" HEAD:gh-pages
+
+  verify-dnf:
+    name: Install from the RPM repository
+    needs: publish
+    if: inputs.dry_run
+    runs-on: ubuntu-latest
+    container: fedora:latest
+    steps:
+      - uses: actions/download-artifact@v8
+        with:
+          name: pages
+          path: pages
+
+      # A real run signs the package and the repository metadata with the one
+      # key from the secret. A dry run has no secret, so each job made a key of
+      # its own and both public halves are needed to check both signatures.
+      - uses: actions/download-artifact@v8
+        with:
+          name: rpm
+          path: signer
+
+      - name: Install from the repository that was just built
+        run: |
+          rpm --import pages/KEY.gpg
+          rpm --import signer/rpm-signer.asc
+          cat > /etc/yum.repos.d/middleclick-autoscroll.repo <<EOF
+          [middleclick-autoscroll]
+          name=middleclick-autoscroll
+          baseurl=file://$PWD/pages/rpm
+          enabled=1
+          gpgcheck=1
+          repo_gpgcheck=1
+          gpgkey=file://$PWD/pages/KEY.gpg
+          EOF
+          # util-linux is for runuser below; the base image does not carry it,
+          # and util-linux-core is not the half that has it.
+          dnf install -y middleclick-autoscroll util-linux
+
+          # As somebody, not as root: running it as root is refused, which is
+          # the point of it, and a container is root by default.
+          useradd -m tester
+          runuser -u tester -- middleclick-autoscroll --version
+          runuser -u tester -- middleclick-autoscroll list

.gitignore

@@ -1,3 +1,6 @@
 # build artifacts
 po/*.mo
 doc/*.1
+
+# packages
+dist/

Makefile

@@ -8,7 +8,7 @@
 # Overridable so a packager can pass the version it is actually building
 # (`make VERSION=$pkgver`). The literal below is the fallback for builds
 # straight from a checkout, and is what a release tag has to carry.
-VERSION      ?= 1.0.1
+VERSION      ?= 1.5.0
 
 PREFIX       ?= /usr
 DESTDIR      ?=
@@ -17,7 +17,24 @@ DATADIR      ?= $(PREFIX)/share
 LIBDIR       ?= $(DATADIR)/middleclick-autoscroll/lib
 LOCALEDIR    ?= $(DATADIR)/locale
 MANDIR       ?= $(DATADIR)/man
-USERUNITDIR  ?= $(PREFIX)/lib/systemd/user
+
+# Where systemd looks for user units. For a normal install into /usr this is
+# asked of systemd itself, because the answer is not the same everywhere - a
+# distribution that still keeps /lib separate from /usr/lib says so here - and
+# only guessed at when there is no systemd installed to ask.
+#
+# A build with a prefix of its own keeps the units under that prefix instead,
+# and under share rather than lib. systemd searches both for a system prefix,
+# but only share for a home one: $XDG_DATA_HOME/systemd/user is a search path
+# and ~/.local/lib/systemd/user is not, so an install into ~/.local that put
+# the units in lib would leave the watcher impossible to enable. That prefix is
+# the one an atomic distribution leaves a user - there is no writing to /usr on
+# Bazzite or Silverblue without layering a package and rebooting.
+ifeq ($(PREFIX),/usr)
+USERUNITDIR  ?= $(shell pkg-config --variable=systemduserunitdir systemd 2>/dev/null || echo /usr/lib/systemd/user)
+else
+USERUNITDIR  ?= $(DATADIR)/systemd/user
+endif
 
 LINGUAS      := de
 MOFILES      := $(patsubst %,po/%.mo,$(LINGUAS))
@@ -28,12 +45,18 @@ LIBS         := $(wildcard src/lib/*.sh)
 MSGFMT       := $(shell command -v msgfmt 2>/dev/null)
 SCDOC        := $(shell command -v scdoc 2>/dev/null)
 
-.PHONY: all build install uninstall check clean
+.PHONY: all build install uninstall check clean version
 
 all: build
 
 build: $(MOFILES) $(MANPAGE)
 
+# The one place the version is written down, for everything that has to agree
+# with it: the packaging scripts, and the release workflow checking that the
+# tag it was handed says the same thing.
+version:
+	@echo $(VERSION)
+
 po/%.mo: po/%.po
 ifdef MSGFMT
 	$(MSGFMT) --check --output-file=$@ $<

README.md

@@ -1,181 +1,133 @@
 # middleclick-autoscroll
 
-Middle-click autoscroll — hold the middle mouse button, move the pointer, the
+middleclick-autoscroll (what a great name, wow) is a CLI for linux that enables autoscroll in every application that supports it.
-page scrolls — for every Chromium-based application on the system. Discord,
+Works with browsers, electron apps like discord and spotify, steam, and anything else that runs on chromium.
-Vesktop, Equibop, VS Code, Obsidian, Signal, Spotify, Steam, Chromium-based
-browsers, and whatever gets installed next week.
 
-```bash
+This tool looks at which of your apps run chromium under the hood and applies the necessary steps to get autoscrolling working (often just a feature flag). One install, one command and autoscroll _✨just works✨_ (like on windows).
-paru -S middleclick-autoscroll
-middleclick-autoscroll enable
-```
 
-That is the whole setup. Nothing else has to be configured, and no file has to
+## How to use
-be edited.
 
-## Why this needs a program at all
+Just run `middleclick-autoscroll`. This will open the configuration TUI that looks like this:
-
-Blink — the engine inside Chromium, Electron and CEF — has had Windows-style
-autoscroll for years. On Linux it is switched off, because middle click is
-already taken by primary-selection paste. One command line argument turns it
-back on:
-
-```
---enable-blink-features=MiddleClickAutoscroll
-```
-
-Getting that argument into one application is a five-minute job. Getting it into
-all of them, in a way that survives the next package upgrade, is not:
-
-- Some applications read a flag file, some don't.
-- Some ship their own copy of Electron, some use the system one.
-- Flatpaks see none of the host's configuration.
-- An application that starts itself at login uses a different entry than the one
-  in the menu, and Discord launched at login used to behave differently from
-  Discord launched by hand.
-- Steam takes no arguments for its interface at all, and puts back any file you
-  change.
-- Every upgrade can undo the lot.
-
-## The interface
-
-`middleclick-autoscroll` on its own:
 
 ```
   Middle-Click Autoscroll
 
   Autoscroll                     ON
 
-  Applications covered           14 of 15
+  Applications covered           11 of 13
   Not identified                 1 - see the applications list
   Steam                          ON
   New applications               ON
-  Last applied                   3 minutes ago
+  Middle-click paste             off
+  Last applied                   2 minutes ago
 
   Applications pick this up the next time they are started.
 
   [1] Turn autoscroll on or off
-  [2] Apply now
+  [2] Re-apply everything
   [3] Applications
   [4] Settings
   [q] Quit
+
+  >
 ```
 
-**[3] Applications** lists everything that was found, how each one is handled,
+Normally you just need to press `[1]` and the magic is done.
-and lets a single application be switched off — or an unrecognised one switched
+Pressing `[3]` lets you see every app that was found and toggle each one individually. 
-on — with the space bar:
 
 ```
   Applications
 
-  ▸ Vesktop                            on (flag file)
+  ▸ Steam                              on (Steam)
+    Chromium                           on (launcher)
     Discord                            on (flag file)
-    Code - OSS                         on (flag file)
+    Obsidian                           on (launcher)
-    Obsidian                           on (flag file)
-    Signal                             on (flag file)
     Spotify                            on (launcher)
-    Steam                              on (Steam)
+    Slack                              off
     Cursor                             cannot tell
+
+  Up/Down select - Space turns one on or off - q goes back
 ```
 
-**[4] Settings** has the categories — Electron and CEF applications, browsers,
+You can also press `[4]` for more settings.
-Flatpaks, autostart entries, Steam, Spotify, whether to watch for new
-applications, and a field for extra Chromium arguments if you want any.
 
-There is a configuration file behind all of this. You are never asked to open
+## How to install
-it.
 
-## Where the argument actually goes
+**Arch (for the cachyos enjoyers)**
-
-Two routes, picked per application.
-
-| | |
-|---|---|
-| **Flag file** | Arch's Electron and Chromium wrappers read extra arguments from `~/.config/<name>-flags.conf`. This is the good one: it is the supported way to pass arguments, it survives package upgrades untouched, and it applies to a launch from a terminal as much as one from the menu. |
-| **Desktop entry** | For applications that ship their own binary with no wrapper, and for Flatpaks, a copy of the entry with the argument appended goes into `~/.local/share/applications`, where it shadows the system one. |
-
-Entries that already live in `~/.local/share/applications` — AppImages, web app
-shortcuts — are edited in place and the original is kept. So are the entries in
-`~/.config/autostart`, so an application that starts itself at login gets the
-same treatment as one started from the menu.
-
-An `--enable-blink-features` that is already there is **extended**, never
-repeated. Chromium keeps only the last occurrence of that option, so a second
-one would silently switch off whatever the first one enabled.
-
-## Steam
-
-Steam's interface is CEF and supports the feature perfectly well, but Steam
-builds the command line for its web helper itself and offers no way to add to
-it. The only place an argument fits is the script that starts the helper, inside
-Steam's own installation:
-
-```
-~/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
-```
-
-Steam checksums that script at every start and restores it when it differs, so
-its launcher entry also gets `-noverifyfiles`. **The trade-off is real**: with
-verification off, Steam no longer repairs a damaged installation by itself. That
-is why Steam is a switch of its own rather than part of the general handling —
-turn it off in the settings and Steam is left completely alone.
-
-The script comes back on every client update. The watcher notices and puts the
-patch back.
-
-Starting Steam from a terminal without `-noverifyfiles` undoes it for that one
-session; the next start from the menu has it again.
-
-## Applications installed later
-
-A systemd user path unit watches every directory a launcher can appear in —
-`/usr/share/applications`, the Flatpak exports, `~/.local/share/applications`,
-`~/.config/autostart` — plus Steam's helper script. Anything new is handled
-within a second of being installed, whether it came from pacman, the AUR,
-Flatpak or an AppImage manager. There is no hook to install per package manager.
-
-## What it will not guess
-
-An AppImage keeps its payload in a compressed filesystem, so there is no way to
-tell from the outside whether Chromium is in there. Those show up as **cannot
-tell** and are left alone until you switch them on from the applications screen.
-
-Detection is deliberately conservative everywhere else too. A wrong "yes" would
-append an unknown argument to something that is not Chromium, and plenty of
-programs treat an unrecognised argument as a file name to open.
-
-## Undoing it
 
 ```bash
-middleclick-autoscroll disable
+yay -S middleclick-autoscroll
 ```
 
-Every change is recorded in a ledger as it is made, and `disable` replays it
+**Fedora (for the mentally stable)**
-backwards: generated entries are deleted, edited files are restored from their
-backups, flag files that only ever contained our line are removed, and a flag
-file that was merged into loses exactly the one feature that was added to it.
-Files that were not touched by this program are not touched by it now either.
 
-Run this before uninstalling the package.
+```bash
+sudo curl -fsSL -o /etc/yum.repos.d/middleclick-autoscroll.repo \
+  https://felitendo.github.io/middleclick-autoscroll/middleclick-autoscroll.repo
+sudo dnf install middleclick-autoscroll
+```
+
+**Bazzite (for the reboot enjoyers)**
+
+```bash
+sudo curl -fsSL -o /etc/yum.repos.d/middleclick-autoscroll.repo \
+  https://felitendo.github.io/middleclick-autoscroll/middleclick-autoscroll.repo
+sudo rpm-ostree install middleclick-autoscroll
+systemctl reboot
+```
+
+**Debian (for the elderly)**
+
+```bash
+sudo install -d -m 0755 /etc/apt/keyrings
+curl -fsSL https://felitendo.github.io/middleclick-autoscroll/KEY.gpg \
+  | sudo gpg --dearmor -o /etc/apt/keyrings/middleclick-autoscroll.gpg
+echo "deb [signed-by=/etc/apt/keyrings/middleclick-autoscroll.gpg] https://felitendo.github.io/middleclick-autoscroll/deb ./" \
+  | sudo tee /etc/apt/sources.list.d/middleclick-autoscroll.list
+sudo apt update && sudo apt install middleclick-autoscroll
+```
+
+**openSUSE (for the both of you)**
+
+```bash
+sudo rpm --import https://felitendo.github.io/middleclick-autoscroll/KEY.gpg
+sudo zypper addrepo --gpgcheck --refresh \
+  https://felitendo.github.io/middleclick-autoscroll/rpm middleclick-autoscroll
+sudo zypper install middleclick-autoscroll
+```
+
+## How it works
+
+Blink (the engine in Chromium, Electron, and CEF) already has autoscroll, but
+it's off on Linux by default because middle click normally pastes the clipboard (??).
+This flag turns it on:
+
+--enable-blink-features=MiddleClickAutoscroll
+
+But doing that for every app is kinda bothersome and it also might break with updates.
+That's why I created this small tool to automate that.
+
+Browsers get the same thing but this time without "blink":
+
+--enable-features=MiddleClickAutoscroll
+
+But both do the same ¯\_(ツ)_/¯
+
+New apps are picked up by a systemd path unit that watches the
+relevant directories. If you hate systemd; `middleclick-autoscroll apply` does the
+same thing manually.
 
 ## Commands
 
-| | |
+| Command | |
 |---|---|
-| `middleclick-autoscroll` | the menu above |
+| `middleclick-autoscroll` | Interactive menu |
-| `… enable` | turn it on, apply, start watching |
+| `… enable` | Turn on, apply, start watching |
-| `… disable` | turn it off and put everything back |
+| `… disable` | Undo everything |
-| `… apply` | apply to anything new (this is what the watcher calls) |
+| `… apply` | Apply to new apps |
-| `… status` | what is covered |
+| `… apply --rebuild` | Redo from scratch |
-| `… list` | every application that was found and how it is handled |
+| `… status` | What's covered |
-
+| `… list` | All apps and how they're handled |
-See `man middleclick-autoscroll` for the details.
-
-## Requirements
-
-Arch or an Arch derivative (CachyOS, EndeavourOS, Manjaro), bash, systemd for
-the watcher. Nothing outside your home directory is ever written to, and running
-it as root is refused.
 
 ## Building from source
 
@@ -184,7 +136,12 @@ make
 sudo make install
 ```
 
-`make check` runs `bash -n` and, if installed, `shellcheck` over every script.
+Optionally needs `msgfmt` (gettext) for translations and `scdoc` for the man
+page. Supports `PREFIX` and `DESTDIR`. `make check` runs syntax checks and
+shellcheck.
+
+See [packaging/README.md](packaging/README.md) for release builds and repo
+signing.
 
 ## License
 

doc/middleclick-autoscroll.1.scd

@@ -2,7 +2,7 @@ middleclick-autoscroll(1)
 
 # NAME
 
-middleclick-autoscroll - middle-click autoscroll for Chromium-based applications
+middleclick-autoscroll - middle-click autoscroll in every application that supports it
 
 # SYNOPSIS
 
@@ -20,6 +20,19 @@ on the command line.
 and puts that argument somewhere the application will actually read it, then
 keeps doing so for anything installed later.
 
+A browser is given *--enable-features=MiddleClickAutoscroll* instead. It asks
+for the same feature - Blink generates a feature of that name for each of its
+runtime flags - but it is not on the list of flags Chromium warns about, so the
+browser does not put a bar reading "You are using an unsupported command-line
+flag" above every page. That spelling only works from Chromium 124 onwards,
+which is why everything else keeps the first one: an application that embeds an
+older Chromium, such as Steam's CEF, has no such bar to show anyway. Helium
+knows the feature under a name of its own and is asked for
+*HeliumMiddleClickAutoscroll* as well; a name a browser does not know is
+ignored. It works on any distribution:
+which of the routes below an application takes is read off its launcher, not
+assumed from where the launcher came from.
+
 Run without a command it shows an interactive menu. Everything it can be told
 is reachable from there; the configuration file behind it does not need to be
 edited by hand.
@@ -36,10 +49,17 @@ is refused.
 *disable*
 	Turn it off and put every file that was changed back the way it was.
 
-*apply*
+*apply* [*--rebuild*]
 	Apply to anything that has appeared since the last run. This is what the
 	watcher calls; running it by hand is only needed when the watcher is off.
 
+	Entries left behind by an application that has since been uninstalled are
+	removed here too - the entry shadowing it lives in the user's home, where
+	the package manager that removed the application cannot see it.
+
+	With *--rebuild* everything is taken back first and written again from
+	scratch. That is the repair: it does not care what looks correct already.
+
 *status*
 	How many applications are covered, whether Steam is patched, and when the
 	last run was.
@@ -59,20 +79,30 @@ is refused.
 Two ways, chosen per application.
 
 *Flag file*
-	Arch's Electron and Chromium wrappers read extra arguments from
+	Where the launcher reads extra arguments from
 	_$XDG_CONFIG_HOME/<name>-flags.conf_. This is the preferred route: it is
 	the supported way to pass arguments, it survives package upgrades, and it
-	applies to a launch from a terminal as much as one from the menu. An
+	applies to a launch from a terminal as much as one from the menu. A
-	*--enable-blink-features* line that is already in the file is extended
+	feature list that is already in the file is extended rather than
-	rather than duplicated - Chromium keeps only the last occurrence of that
+	duplicated - Chromium keeps only the last occurrence of such an option, so
-	option, so a second one would switch the first one off.
+	a second one would switch the first one off.
+
+	Arch's Electron and Chromium packages all wrap their binaries this way, and
+	so do a number of individual vendors' launchers elsewhere. Whether a given
+	launcher does is read off the launcher itself, never assumed from the
+	distribution: only one that really names such a file takes this route.
 
 *Desktop entry*
 	For applications that ship their own binary with no wrapper, and for
-	Flatpaks, a copy of the desktop entry with the argument appended is written
+	everything inside a Flatpak or a snap, a copy of the desktop entry with the
-	to _~/.local/share/applications_, where it shadows the system one. Entries
+	argument appended is written to _~/.local/share/applications_, where it
-	that already live there - AppImages, web app shortcuts - are edited in
+	shadows the system one. Entries that already live there - AppImages, web
-	place, with the original kept.
+	app shortcuts - are edited in place, with the original kept.
+
+	This is the route everything takes on the distributions whose Chromium
+	wrappers keep their equivalent file under _/etc_, where it is the system's
+	to write and not the user's: Debian, Ubuntu, Fedora and openSUSE among
+	them.
 
 	A generated entry is marked *X-MCA-Generated* and an entry edited in place
 	*X-MCA-Patched*. The two are never confused: the first is deleted when
@@ -83,6 +113,13 @@ Programs that start themselves at login write their own entry into
 _~/.config/autostart_ pointing straight at their binary, bypassing the menu
 entry entirely. Those are patched in place as well.
 
+Shortcuts on the desktop itself are patched in place too. Nothing in the XDG
+search path looks at that folder, so a shortcut that lives only there would
+otherwise be invisible - and Steam puts one there for every game somebody asks
+for a shortcut to. The folder's name is translated, and the name in use is read
+from _~/.config/user-dirs.dirs_ rather than guessed; the watcher is told about
+it in a drop-in written when autoscroll is turned on.
+
 # STEAM
 
 Steam's interface is CEF and supports the feature, but Steam builds the command
@@ -91,22 +128,78 @@ helper, inside Steam's own installation:
 
 	~/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
 
-Steam checksums that script at every start and restores it when it differs, so
+Where that installation is depends on how Steam was installed:
-its launcher entry also gets *-noverifyfiles*. The trade-off is that Steam no
+_~/.local/share/Steam_ for Valve's own package and Arch's,
-longer repairs a damaged installation on its own; that is why Steam is a switch
+_~/.steam/debian-installation_ for Debian's, and the private tree of the
-of its own in the settings.
+sandbox for the Flatpak and the snap. All of them are looked at.
 
-Starting Steam from a terminal without *-noverifyfiles* undoes the patch for
+Steam compares the installed files against its manifest at every start - by
-that session. The watcher notices and puts it back, so the next start has it
+size and timestamp rather than by content - and restores whatever differs. So
-again.
+the patch is written to look untouched: the bytes the argument costs are taken
+back out of the script's own comments and the timestamp is put back afterwards,
+leaving a file exactly as long and exactly as old as Steam left it. A client
+that checks its files finds nothing to repair, and the argument survives
+however Steam was started - from the menu, from a game shortcut, from a
+launcher like Heroic or Lutris, from a terminal.
+
+That is what has to work, because it is the only thing that does. A patch that
+changes the length is never written, whatever else could be done to cover for
+it: Steam checks its files at the shutdown it runs itself as well as at a start
+it was given arguments for, and that one carries no arguments of anybody's. One
+wrong length costs the whole client package downloaded, extracted and installed
+again, and a client that quits at the end of it instead of coming up.
+
+So where the comments cannot pay for the argument, or a client update has
+changed how the helper is started, nothing is written and the status screen
+says Steam is not patched. Nothing goes on Steam's launcher entry, its
+autostart entry or the shortcuts it writes for single games either, and Steam
+goes on repairing its own installation.
+
+An installation patched by an earlier version, which appended where the
+comments were short, is written again to fit at the next apply, or taken back
+if it cannot be made to.
+
+A client update brings a new version of the script. The watcher notices and
+patches it again, and the copy kept for undoing is replaced with the new
+version at the same time, so undoing puts back the script Steam last shipped
+rather than the one from before the update.
 
 # SPOTIFY
 
 The official client is CEF rather than Electron. Installed through
 *spotify-launcher*, it is started by a program that builds its own command line
 and has a configuration file with a slot for extra arguments; that slot is
-where the flag goes. Installed as a plain package, it is an ordinary desktop
+where the flag goes. Installed as a plain package, a Flatpak or a snap, it is
-entry and needs nothing special.
+an ordinary desktop entry and needs nothing special.
+
+# MIDDLE-CLICK PASTE
+
+Inside a Chromium application the argument settles this on its own: with
+autoscroll on, Blink stops pasting the primary selection on middle click,
+because the button is doing something else now. Everywhere else on the desktop
+middle click goes on pasting, so the desktop's own switch for it is turned off
+too.
+
+KDE has such a switch, and only for a Wayland session, where the paste is a
+protocol the compositor either offers or does not:
+
+	~/.config/kwinrc, [Wayland], EnablePrimarySelection=false
+
+It is written with *kwriteconfig6*, the same tool System Settings uses, because
+kwinrc has a cascade behind it and entries a distribution can mark immutable;
+an edit that reaches past all that writes something KDE goes on to ignore. KWin
+reads the key once, while it starts, so the change is true from the next login
+on rather than straight away.
+
+What the key said before is recorded, and *disable* puts that back. A key that
+already said *false* before any of this is left alone and not recorded either,
+so a paste the user switched off themselves is never switched back on.
+
+On X11 there is nothing to switch. The primary selection is part of X itself
+and every toolkit reaches for it on its own; no one place can say no. The
+status screen leaves the row out where there is nothing to report.
+
+Turn it off under *Settings* to keep the desktop's middle-click paste.
 
 # WHAT CANNOT BE DETECTED
 
@@ -126,6 +219,11 @@ _~/.local/state/middleclick-autoscroll/ledger_
 _~/.local/state/middleclick-autoscroll/backup/_
 	Copies of the files that are edited in place rather than shadowed.
 
+_~/.config/kwinrc_
+	KDE's own configuration. One key in it, *EnablePrimarySelection*, is
+	written when the desktop's middle-click paste is turned off, and put
+	back by *disable*.
+
 _~/.cache/middleclick-autoscroll/detect_
 	Which programs were found to be Chromium, keyed by size and modification
 	time. Safe to delete.
@@ -135,9 +233,15 @@ _~/.cache/middleclick-autoscroll/detect_
 *NO_COLOR*
 	Disables colour.
 
+# REQUIREMENTS
+
+Bash 4.2 or newer and GNU coreutils. The watcher needs a systemd user session;
+without one everything else works and applications installed later are picked
+up at the next *apply* rather than on their own.
+
 # SEE ALSO
 
-*systemctl*(1), *flatpak*(1)
+*systemctl*(1), *flatpak*(1), *snap*(8), *kwriteconfig6*(1)
 
 # AUTHORS
 

packaging/README.md

@@ -0,0 +1,88 @@
+# Packaging and releases
+
+The Makefile installs everything; these only wrap what it produced. That is
+deliberate — a packaging script that lists the files again is a second
+description of the layout, and two descriptions drift.
+
+| | |
+|---|---|
+| `deb/control`, `deb/copyright` | metadata for the Debian binary package |
+| `rpm/middleclick-autoscroll.spec` | the RPM spec |
+| `build-deb.sh`, `build-rpm.sh` | build one package into `dist/` |
+| `check-version.sh` | refuses a tag that disagrees with the Makefile |
+| `publish-repos.sh` | regenerates the APT and RPM repositories |
+| `pages/` | the landing page and the `.repo` file served from GitHub Pages |
+
+Neither package carries a maintainer script. The units are enabled per user by
+the program itself, and there is nothing to do as root at install time.
+
+## Building one by hand
+
+```bash
+packaging/build-deb.sh      # needs dpkg-dev, gettext, scdoc
+packaging/build-rpm.sh      # needs rpm-build, gettext, scdoc, systemd-rpm-macros
+```
+
+Both take the version from `make version` unless one is passed as the first
+argument.
+
+## Making a release
+
+1. Bump `VERSION` in the Makefile.
+2. Commit, then `git tag vX.Y.Z && git push --tags`.
+
+The `release` workflow builds both packages in a Debian and a Fedora container,
+refuses the tag if it disagrees with the Makefile, attaches the packages to a
+GitHub release, and adds them to the APT and RPM repositories on the `gh-pages`
+branch. Nothing else has to be done by hand.
+
+## Trying the release path first
+
+```bash
+gh workflow run release.yml -f dry_run=true
+```
+
+Builds both packages, builds both repositories with a key generated on the
+spot, checks the three signatures it wrote, and then installs the packages back
+out of the repositories — apt on the runner, dnf in a Fedora container. Nothing
+is pushed and no release is made. This is worth running after any change to the
+packaging, because the alternative is finding out from a tag.
+
+## Setting up the signing, once
+
+The repositories are signed, so this needs a key. Make one that exists for
+nothing else — not a personal key — and give it no passphrase: it lives as an
+encrypted repository secret, and `rpmsign` cannot be handed a passphrase
+unattended.
+
+```bash
+gpg --batch --passphrase '' --quick-generate-key \
+    'middleclick-autoscroll repository <felitendoyt@gmail.com>' rsa4096 sign never
+
+gpg --armor --export-secret-keys 'middleclick-autoscroll repository' \
+    | gh secret set GPG_PRIVATE_KEY
+```
+
+Without the secret the workflow still builds both packages and attaches them to
+the release; it says so in the log and leaves the repositories alone.
+
+## Pointing Pages at it, once — and in this order
+
+The `gh-pages` branch does not exist until a release has put something on it,
+and a branch that does not exist cannot be picked in the Pages settings. So:
+
+1. Set the secret, above.
+2. Tag a release. The workflow creates the branch and fills it.
+3. *Then* set **Pages** to deploy from a branch and pick `gh-pages` at the
+   root.
+
+Doing it the other way round is a wall, and leaving Pages pointed at `main`
+serves the source tree at the address the install instructions name — the key
+and the indexes are 404 and nothing installs.
+
+## What users end up with
+
+The public key is published as `KEY.gpg` beside the repositories, and the
+landing page carries the setup lines for each distribution. After that, a new
+version arrives with `apt upgrade`, `dnf upgrade` or `zypper up` like anything
+else.

packaging/build-deb.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+#
+# Builds the binary package for Debian, Ubuntu and their derivatives into
+# dist/.
+#
+# Everything the package contains comes out of `make install`. This only wraps
+# what that produced, so there is exactly one description of where a file goes
+# and it is the Makefile - a packaging script that lists the files again is a
+# second description, and the two drift.
+#
+# Needs: make, dpkg-deb, msgfmt (gettext), scdoc.
+
+set -euo pipefail
+
+here="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+version="${1:-$(make -s -C "$here" version)}"
+name=middleclick-autoscroll
+
+# A package without its man page or its translations is not a package this
+# should be quietly willing to produce: the Makefile skips both when the tools
+# are missing, and the result would look like a successful build.
+for tool in msgfmt scdoc dpkg-deb; do
+	command -v "$tool" > /dev/null || { echo "$0: $tool is not installed" >&2; exit 1; }
+done
+
+root="$(mktemp -d)"
+trap 'rm -rf -- "$root"' EXIT
+
+make -C "$here" install \
+	DESTDIR="$root" \
+	PREFIX=/usr \
+	VERSION="$version" \
+	USERUNITDIR=/usr/lib/systemd/user
+
+install -d "$root/DEBIAN"
+sed "s|@VERSION@|$version|g" "$here/packaging/deb/control" > "$root/DEBIAN/control"
+install -Dm644 "$here/packaging/deb/copyright" \
+	"$root/usr/share/doc/$name/copyright"
+
+# Relative to the package root, and DEBIAN/ itself is not part of the contents.
+# Sorted in the C locale so the file comes out the same whatever the locale of
+# the machine that built it.
+( cd "$root" && find . -type f ! -path './DEBIAN/*' -printf '%P\0' \
+	| LC_ALL=C sort -z | xargs -0 md5sum > DEBIAN/md5sums )
+
+mkdir -p "$here/dist"
+out="$here/dist/${name}_${version}_all.deb"
+dpkg-deb --root-owner-group --build "$root" "$out" > /dev/null
+
+echo "$out"

packaging/build-rpm.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+#
+# Builds the binary package for Fedora, RHEL, openSUSE and their derivatives
+# into dist/.
+#
+# The spec takes the version as a macro rather than carrying one of its own,
+# for the same reason the Debian control file has a placeholder: the Makefile
+# is where the version is written down.
+#
+# Needs: rpmbuild, make, msgfmt (gettext), scdoc, systemd-rpm-macros.
+
+set -euo pipefail
+
+here="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+version="${1:-$(make -s -C "$here" version)}"
+name=middleclick-autoscroll
+
+command -v rpmbuild > /dev/null || { echo "$0: rpmbuild is not installed" >&2; exit 1; }
+
+top="$(mktemp -d)"
+trap 'rm -rf -- "$top"' EXIT
+mkdir -p "$top"/{BUILD,BUILDROOT,RPMS,SOURCES,SPECS}
+
+# The working tree as it is, not as it was committed: a package built from a
+# checkout has to contain what is in that checkout.
+tar czf "$top/SOURCES/$name-$version.tar.gz" \
+	--transform "s,^\\.,$name-$version," \
+	--exclude=./.git --exclude=./dist --exclude=./po/'*.mo' \
+	-C "$here" .
+
+rpmbuild \
+	--define "_topdir $top" \
+	--define "_version $version" \
+	-bb "$here/packaging/rpm/$name.spec" > /dev/null
+
+mkdir -p "$here/dist"
+cp "$top"/RPMS/noarch/*.rpm "$here/dist/"
+
+ls "$here/dist/$name-$version"*.rpm

packaging/check-version.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+#
+# Refuses a release whose tag and Makefile disagree.
+#
+# The version is baked into the program at install time from the Makefile, and
+# the packages take theirs from the same place - but the tag is what people see
+# and what the release is named after. A tag that says something else produces
+# a package called 1.0.4 containing a program that reports 1.0.3, and nothing
+# would have complained.
+#
+# Anything that is not a v-tag - a run started by hand from a branch - is not a
+# release and has nothing to check.
+
+set -euo pipefail
+
+here="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+ref="${1:-}"
+
+case "$ref" in
+	v[0-9]*) ;;
+	*)
+		echo "not a release tag (${ref:-none}) - nothing to check against"
+		exit 0
+		;;
+esac
+
+tag_version="${ref#v}"
+make_version="$(make -s -C "$here" version)"
+
+if [[ $tag_version != "$make_version" ]]; then
+	echo "tag $ref says $tag_version, the Makefile says $make_version" >&2
+	echo "Bump VERSION in the Makefile to match the tag, or retag." >&2
+	exit 1
+fi
+
+echo "$ref matches the Makefile"

packaging/deb/control

@@ -0,0 +1,24 @@
+Package: middleclick-autoscroll
+Version: @VERSION@
+Section: utils
+Priority: optional
+Architecture: all
+Maintainer: Felitendo <felitendoyt@gmail.com>
+Depends: bash (>= 4.2), coreutils, findutils, grep, sed, mawk | gawk | original-awk
+Recommends: gettext-base, systemd, desktop-file-utils
+Homepage: https://github.com/Felitendo/middleclick-autoscroll
+Description: middle-click autoscroll for Chromium-based applications
+ Blink - the engine inside Chromium, Electron and CEF - has had Windows-style
+ autoscroll for years: hold the middle mouse button, move the pointer, the page
+ scrolls. On Linux it is switched off, because middle click is already taken by
+ primary-selection paste.
+ .
+ This turns it back on for every application on the system that can do it, and
+ for anything installed later. There is no list of supported applications to
+ keep up to date: every launcher is examined, the ones running on Chromium
+ underneath are identified by what they ship rather than by their name, and the
+ argument goes wherever that particular application will actually read it.
+ .
+ Nothing outside the user's home directory is ever written to. Run
+ "middleclick-autoscroll disable" before removing this package, so that
+ everything it changed is put back.

packaging/deb/copyright

@@ -0,0 +1,20 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: middleclick-autoscroll
+Source: https://github.com/Felitendo/middleclick-autoscroll
+
+Files: *
+Copyright: 2026 Felitendo
+License: GPL-3+
+
+License: GPL-3+
+ This program is free software: you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free Software
+ Foundation, either version 3 of the License, or (at your option) any later
+ version.
+ .
+ This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ .
+ On Debian systems the full text of the GNU General Public License version 3 can
+ be found in /usr/share/common-licenses/GPL-3.

packaging/pages/index.html

@@ -0,0 +1,115 @@
+<!doctype html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<title>middleclick-autoscroll</title>
+<style>
+  :root {
+    --bg: #ffffff;
+    --fg: #1b1f23;
+    --muted: #57606a;
+    --rule: #d8dee4;
+    --code-bg: #f6f8fa;
+    --accent: #1793d1;
+  }
+  @media (prefers-color-scheme: dark) {
+    :root:not([data-theme="light"]) {
+      --bg: #0d1117;
+      --fg: #e6edf3;
+      --muted: #9198a1;
+      --rule: #30363d;
+      --code-bg: #161b22;
+      --accent: #58a6ff;
+    }
+  }
+  * { box-sizing: border-box; }
+  body {
+    margin: 0 auto;
+    padding: 3rem 1.25rem 5rem;
+    max-width: 46rem;
+    background: var(--bg);
+    color: var(--fg);
+    font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+          "Helvetica Neue", Arial, sans-serif;
+  }
+  h1 { font-size: 1.6rem; margin: 0 0 .4rem; }
+  h2 {
+    font-size: 1.05rem; margin: 2.5rem 0 .6rem;
+    padding-bottom: .3rem; border-bottom: 1px solid var(--rule);
+  }
+  p.lead { color: var(--muted); margin: 0 0 2rem; }
+  p { margin: 0 0 1rem; }
+  a { color: var(--accent); }
+  code {
+    background: var(--code-bg); padding: .12em .35em;
+    border-radius: 4px; font-size: .9em;
+  }
+  pre {
+    background: var(--code-bg);
+    border: 1px solid var(--rule);
+    border-radius: 6px;
+    padding: .9rem 1rem;
+    overflow-x: auto;
+  }
+  pre code { background: none; padding: 0; font-size: .85rem; }
+  footer {
+    margin-top: 3.5rem; padding-top: 1rem;
+    border-top: 1px solid var(--rule);
+    color: var(--muted); font-size: .9rem;
+  }
+</style>
+</head>
+<body>
+
+<h1>middleclick-autoscroll</h1>
+<p class="lead">
+  Middle-click autoscroll — hold the middle mouse button, move the pointer, the
+  page scrolls — in every Chromium-based application on the system, and in
+  anything installed later.
+</p>
+
+<p>
+  This page is the package repository. Set it up once and every new version
+  arrives with the rest of your system updates. The
+  <a href="https://github.com/Felitendo/middleclick-autoscroll">source and the
+  documentation</a> are on GitHub.
+</p>
+
+<h2>Debian, Ubuntu, Linux Mint, Pop!_OS</h2>
+<pre><code>sudo install -d -m 0755 /etc/apt/keyrings
+curl -fsSL @BASEURL@/KEY.gpg \
+  | sudo gpg --dearmor -o /etc/apt/keyrings/middleclick-autoscroll.gpg
+echo "deb [signed-by=/etc/apt/keyrings/middleclick-autoscroll.gpg] @BASEURL@/deb ./" \
+  | sudo tee /etc/apt/sources.list.d/middleclick-autoscroll.list
+sudo apt update
+sudo apt install middleclick-autoscroll</code></pre>
+
+<h2>Fedora, RHEL, CentOS Stream</h2>
+<pre><code>sudo curl -fsSL -o /etc/yum.repos.d/middleclick-autoscroll.repo \
+  @BASEURL@/middleclick-autoscroll.repo
+sudo dnf install middleclick-autoscroll</code></pre>
+
+<h2>openSUSE</h2>
+<pre><code>sudo rpm --import @BASEURL@/KEY.gpg
+sudo zypper addrepo --gpgcheck --refresh @BASEURL@/rpm middleclick-autoscroll
+sudo zypper install middleclick-autoscroll</code></pre>
+
+<h2>Arch, CachyOS, EndeavourOS, Manjaro</h2>
+<pre><code>paru -S middleclick-autoscroll</code></pre>
+
+<h2>Then, once</h2>
+<pre><code>middleclick-autoscroll enable</code></pre>
+<p>
+  That is the whole setup. Nothing else has to be configured and no file has to
+  be edited. Run <code>middleclick-autoscroll disable</code> before removing the
+  package — it puts back everything that was changed.
+</p>
+
+<footer>
+  GPL-3.0-or-later. Packages are signed; the public key is
+  <a href="@BASEURL@/KEY.gpg">KEY.gpg</a>.
+</footer>
+
+</body>
+</html>

packaging/pages/middleclick-autoscroll.repo

@@ -0,0 +1,7 @@
+[middleclick-autoscroll]
+name=middleclick-autoscroll
+baseurl=@BASEURL@/rpm
+enabled=1
+gpgcheck=1
+repo_gpgcheck=1
+gpgkey=@BASEURL@/KEY.gpg

packaging/publish-repos.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+#
+# Puts the packages that were just built into the APT and RPM repositories on
+# the gh-pages branch, and regenerates the indexes over everything that is
+# there.
+#
+# Old versions are kept rather than replaced. An index built over all of them
+# is what lets somebody pin a version or go back to one, and it costs a few
+# hundred kilobytes.
+#
+# Usage: publish-repos.sh <gh-pages checkout> <directory of new packages>
+#
+# Needs: dpkg-dev, apt-utils, createrepo-c, gpg, and a secret key already
+# imported - its id is taken from the keyring.
+
+set -euo pipefail
+
+pages="$(cd -- "$1" && pwd)"
+incoming="$(cd -- "$2" && pwd)"
+here="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+
+base_url="${MCA_REPO_URL:-https://felitendo.github.io/middleclick-autoscroll}"
+
+keyid="$(gpg --list-secret-keys --with-colons | awk -F: '/^sec:/ { print $5; exit }')"
+[[ -n $keyid ]] || { echo "$0: no secret key in the keyring" >&2; exit 1; }
+
+mkdir -p "$pages/deb" "$pages/rpm"
+cp -- "$incoming"/*.deb "$pages/deb/"
+cp -- "$incoming"/*.rpm "$pages/rpm/"
+
+# ---------------------------------------------------------------------------
+# APT
+# ---------------------------------------------------------------------------
+# A flat repository: the packages and their index sit in one directory and the
+# sources line ends in "./". There is one distribution here and it is the same
+# package for all of them, so the suite and component machinery of a pool
+# layout would describe nothing.
+(
+	cd "$pages/deb"
+
+	# The old index must be gone before the new one is written: apt-ftparchive
+	# hashes every file in the directory, and a Release that hashes the
+	# previous Release is a Release that cannot be verified.
+	rm -f Packages Packages.gz Release Release.gpg InRelease
+
+	dpkg-scanpackages --multiversion . > Packages
+	gzip -9kf Packages
+
+	apt-ftparchive \
+		-o APT::FTPArchive::Release::Origin=middleclick-autoscroll \
+		-o APT::FTPArchive::Release::Label=middleclick-autoscroll \
+		-o APT::FTPArchive::Release::Suite=stable \
+		-o APT::FTPArchive::Release::Codename=stable \
+		-o APT::FTPArchive::Release::Architectures=all \
+		-o APT::FTPArchive::Release::Components=main \
+		release . > Release
+
+	# Both signatures: InRelease is what current apt fetches, Release.gpg is
+	# what an older one falls back to.
+	gpg --batch --yes --local-user "$keyid" --clearsign --output InRelease Release
+	gpg --batch --yes --local-user "$keyid" --detach-sign --armor --output Release.gpg Release
+)
+
+# ---------------------------------------------------------------------------
+# RPM
+# ---------------------------------------------------------------------------
+(
+	cd "$pages/rpm"
+	createrepo_c --quiet --update .
+	rm -f repodata/repomd.xml.asc
+	gpg --batch --yes --local-user "$keyid" --detach-sign --armor repodata/repomd.xml
+)
+
+# ---------------------------------------------------------------------------
+# The key and the landing page
+# ---------------------------------------------------------------------------
+gpg --armor --export "$keyid" > "$pages/KEY.gpg"
+
+sed "s|@BASEURL@|$base_url|g" "$here/packaging/pages/index.html" > "$pages/index.html"
+sed "s|@BASEURL@|$base_url|g" "$here/packaging/pages/middleclick-autoscroll.repo" \
+	> "$pages/middleclick-autoscroll.repo"
+
+# Pages would otherwise hand the whole directory to Jekyll, which drops every
+# file whose name starts with an underscore and can rewrite the rest.
+touch "$pages/.nojekyll"
+
+echo "signed with $keyid"
+ls -1 "$pages/deb" "$pages/rpm"

packaging/rpm/middleclick-autoscroll.spec

@@ -0,0 +1,72 @@
+# Built with `packaging/build-rpm.sh`, which passes the version in rather than
+# editing this file: the Makefile is where the version is written down, and two
+# places that have to agree are one place too many.
+%global upstream_version %{?_version}%{!?_version:1.0.3}
+
+Name:           middleclick-autoscroll
+Version:        %{upstream_version}
+Release:        1%{?dist}
+Summary:        Middle-click autoscroll for Chromium-based applications
+
+License:        GPL-3.0-or-later
+URL:            https://github.com/Felitendo/middleclick-autoscroll
+Source0:        %{name}-%{version}.tar.gz
+
+BuildArch:      noarch
+BuildRequires:  make
+BuildRequires:  gettext
+BuildRequires:  scdoc
+# For %{_userunitdir}, which is where the watcher's user units belong.
+BuildRequires:  systemd-rpm-macros
+
+Requires:       bash >= 4.2
+Requires:       coreutils
+Requires:       findutils
+Requires:       grep
+Requires:       sed
+Requires:       gawk
+
+# The interface falls back to English without gettext and picks up new
+# applications at the next `apply` without systemd, so neither is required.
+Recommends:     /usr/bin/gettext
+Recommends:     systemd
+Recommends:     desktop-file-utils
+
+%description
+Blink - the engine inside Chromium, Electron and CEF - has had Windows-style
+autoscroll for years: hold the middle mouse button, move the pointer, the page
+scrolls. On Linux it is switched off, because middle click is already taken by
+primary-selection paste.
+
+This turns it back on for every application on the system that can do it, and
+for anything installed later. There is no list of supported applications to keep
+up to date: every launcher is examined, the ones running on Chromium underneath
+are identified by what they ship rather than by their name, and the argument goes
+wherever that particular application will actually read it.
+
+Nothing outside the user's home directory is ever written to. Run
+"middleclick-autoscroll disable" before removing this package, so that everything
+it changed is put back.
+
+%prep
+%autosetup -n %{name}-%{version}
+
+%build
+%make_build VERSION=%{upstream_version}
+
+%install
+%make_install PREFIX=%{_prefix} VERSION=%{upstream_version} \
+	USERUNITDIR=%{_userunitdir}
+
+%find_lang %{name}
+
+%files -f %{name}.lang
+%license LICENSE
+%doc %{_datadir}/doc/%{name}/README.md
+%{_bindir}/%{name}
+%{_datadir}/%{name}/
+%{_userunitdir}/%{name}.path
+%{_userunitdir}/%{name}.service
+%{_mandir}/man1/%{name}.1*
+
+%changelog

po/de.po

@@ -4,7 +4,7 @@
 #
 msgid ""
 msgstr ""
-"Project-Id-Version: middleclick-autoscroll 1.0.1\n"
+"Project-Id-Version: middleclick-autoscroll 1.0.3\n"
 "Report-Msgid-Bugs-To: https://github.com/Felitendo/middleclick-autoscroll/issues\n"
 "POT-Creation-Date: 2026-08-16 00:00+0200\n"
 "PO-Revision-Date: 2026-08-16 00:00+0200\n"
@@ -63,6 +63,9 @@ msgstr "%d – siehe Anwendungsliste"
 msgid "Steam"
 msgstr "Steam"
 
+msgid "Middle-click paste"
+msgstr "Mittelklick-Einfügen"
+
 msgid "New applications"
 msgstr "Neue Anwendungen"
 
@@ -77,8 +80,8 @@ msgstr "Anwendungen übernehmen das beim nächsten Start."
 msgid "Turn autoscroll on or off"
 msgstr "Autoscroll ein- oder ausschalten"
 
-msgid "Apply now"
+msgid "Re-apply everything"
-msgstr "Jetzt anwenden"
+msgstr "Alles neu anwenden"
 
 msgid "Applications"
 msgstr "Anwendungen"
@@ -103,12 +106,18 @@ msgstr "Chromium-basierte Browser"
 msgid "Flatpak applications"
 msgstr "Flatpak-Anwendungen"
 
+msgid "Snap applications"
+msgstr "Snap-Anwendungen"
+
 msgid "Programs that start themselves at login"
 msgstr "Programme, die sich beim Anmelden selbst starten"
 
 msgid "Spotify"
 msgstr "Spotify"
 
+msgid "Turn off KDE's middle-click paste"
+msgstr "KDEs Mittelklick-Einfügen abschalten"
+
 msgid "Apply to newly installed applications"
 msgstr "Auf neu installierte Anwendungen anwenden"
 
@@ -149,9 +158,6 @@ msgstr "Autoscroll ist für %d Anwendungen an."
 msgid "Applications that are already running pick this up when they are restarted."
 msgstr "Bereits laufende Anwendungen übernehmen das nach einem Neustart."
 
-msgid "Steam's launcher now skips its file check, which is what keeps the change from being undone at every start."
-msgstr "Steams Startereintrag überspringt jetzt die Dateiprüfung – nur so bleibt die Änderung bei jedem Start erhalten."
-
 msgid "Could not start the watcher for newly installed applications."
 msgstr "Die Überwachung neu installierter Anwendungen konnte nicht gestartet werden."
 
@@ -164,14 +170,23 @@ msgstr "Autoscroll ist aus, alle Änderungen wurden zurückgenommen."
 msgid "Autoscroll is off. Turn it on first."
 msgstr "Autoscroll ist aus. Erst einschalten."
 
+msgid "Applied again to %d applications."
+msgstr "Erneut auf %d Anwendungen angewendet."
+
 msgid "Applied to %d applications."
 msgstr "Auf %d Anwendungen angewendet."
 
 msgid "Already applied to %d applications."
 msgstr "Bereits auf %d Anwendungen angewendet."
 
-msgid "Steam starts its interface in a way this version does not recognise; leaving it alone."
+msgid "Steam starts its interface in a way this version cannot change without Steam noticing; leaving it alone."
-msgstr "Steam startet seine Oberfläche auf eine Art, die diese Version nicht kennt; Steam bleibt unangetastet."
+msgstr "Steam startet seine Oberfläche auf eine Art, die diese Version nicht ändern kann, ohne dass Steam es merkt; Steam bleibt unangetastet."
+
+msgid "Steam's interface cannot be given the flag without leaving a file Steam would reinstall; the change has been taken back."
+msgstr "Steams Oberfläche lässt sich das Flag nicht geben, ohne eine Datei zu hinterlassen, die Steam neu installieren würde; die Änderung wurde zurückgenommen."
+
+msgid "Middle click stops pasting at the next login."
+msgstr "Mittelklick fügt ab der nächsten Anmeldung nichts mehr ein."
 
 
 #. Help
@@ -190,6 +205,9 @@ msgstr "Ausschalten und alles zurücknehmen"
 msgid "Apply to anything installed since the last run"
 msgstr "Auf alles anwenden, was seit dem letzten Lauf dazugekommen ist"
 
+msgid "Take everything back and apply it again"
+msgstr "Alles zurücknehmen und neu anwenden"
+
 msgid "Show what is covered"
 msgstr "Anzeigen, was abgedeckt ist"
 

po/middleclick-autoscroll.pot

@@ -4,7 +4,7 @@
 #
 msgid ""
 msgstr ""
-"Project-Id-Version: middleclick-autoscroll 1.0.1\n"
+"Project-Id-Version: middleclick-autoscroll 1.0.3\n"
 "Report-Msgid-Bugs-To: https://github.com/Felitendo/middleclick-autoscroll/issues\n"
 "POT-Creation-Date: 2026-08-16 00:00+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
@@ -63,6 +63,9 @@ msgstr ""
 msgid "Steam"
 msgstr ""
 
+msgid "Middle-click paste"
+msgstr ""
+
 msgid "New applications"
 msgstr ""
 
@@ -77,7 +80,7 @@ msgstr ""
 msgid "Turn autoscroll on or off"
 msgstr ""
 
-msgid "Apply now"
+msgid "Re-apply everything"
 msgstr ""
 
 msgid "Applications"
@@ -103,12 +106,18 @@ msgstr ""
 msgid "Flatpak applications"
 msgstr ""
 
+msgid "Snap applications"
+msgstr ""
+
 msgid "Programs that start themselves at login"
 msgstr ""
 
 msgid "Spotify"
 msgstr ""
 
+msgid "Turn off KDE's middle-click paste"
+msgstr ""
+
 msgid "Apply to newly installed applications"
 msgstr ""
 
@@ -149,9 +158,6 @@ msgstr ""
 msgid "Applications that are already running pick this up when they are restarted."
 msgstr ""
 
-msgid "Steam's launcher now skips its file check, which is what keeps the change from being undone at every start."
-msgstr ""
-
 msgid "Could not start the watcher for newly installed applications."
 msgstr ""
 
@@ -164,13 +170,22 @@ msgstr ""
 msgid "Autoscroll is off. Turn it on first."
 msgstr ""
 
+msgid "Applied again to %d applications."
+msgstr ""
+
 msgid "Applied to %d applications."
 msgstr ""
 
 msgid "Already applied to %d applications."
 msgstr ""
 
-msgid "Steam starts its interface in a way this version does not recognise; leaving it alone."
+msgid "Steam starts its interface in a way this version cannot change without Steam noticing; leaving it alone."
+msgstr ""
+
+msgid "Steam's interface cannot be given the flag without leaving a file Steam would reinstall; the change has been taken back."
+msgstr ""
+
+msgid "Middle click stops pasting at the next login."
 msgstr ""
 
 
@@ -190,6 +205,9 @@ msgstr ""
 msgid "Apply to anything installed since the last run"
 msgstr ""
 
+msgid "Take everything back and apply it again"
+msgstr ""
+
 msgid "Show what is covered"
 msgstr ""
 

res/systemd/middleclick-autoscroll.path

@@ -3,21 +3,39 @@ Description=Watch for newly installed Chromium-based applications
 Documentation=man:middleclick-autoscroll(1)
 
 [Path]
-# Every way an application can turn up: a package, a Flatpak, something
+# Every way an application can turn up: a package, a Flatpak, a snap, something
 # installed by hand. Watching where the launchers land means there is no hook
-# to write per package manager - pacman, flatpak and an AppImage manager all
+# to write per package manager - pacman, apt, dnf, zypper, flatpak, snapd and
-# end up here.
+# an AppImage manager all end up here.
+#
+# A directory that does not exist on this system costs nothing: systemd watches
+# the nearest parent that does and picks the path up when it appears.
 PathModified=/usr/share/applications
 PathModified=/usr/local/share/applications
 PathModified=%h/.local/share/applications
 PathModified=%h/.config/autostart
 PathModified=/var/lib/flatpak/exports/share/applications
 PathModified=%h/.local/share/flatpak/exports/share/applications
+PathModified=/var/lib/snapd/desktop/applications
+
+# NixOS and Guix build the search path out of profiles rather than /usr.
+PathModified=/run/current-system/sw/share/applications
+PathModified=%h/.nix-profile/share/applications
+PathModified=%h/.guix-profile/share/applications
+
+# The desktop folder is watched too - Steam writes a shortcut there for every
+# game somebody asks for one, and starting a game is a Steam start - but its
+# name is translated and cannot be written down here. `enable` adds it in a
+# drop-in, from the name this system uses.
 
 # Steam replaces the script that starts its interface on every client update,
-# which takes the patch with it.
+# which takes the patch with it. Where that installation lives depends on how
+# Steam was installed.
 PathChanged=%h/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
+PathChanged=%h/.steam/debian-installation/ubuntu12_64/steamwebhelper_sniper_wrap.sh
 PathChanged=%h/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
+PathChanged=%h/.var/app/com.valvesoftware.Steam/data/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
+PathChanged=%h/snap/steam/common/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
 
 Unit=middleclick-autoscroll.service
 

src/lib/apply.sh

@@ -10,7 +10,7 @@
 MCA_CHANGES=0
 MCA_ROUTES=()
 
-# mca_route <kind> <id> <program>
+# mca_route <kind> <id> <program> [packaging]
 # What happens to one application, left in MCA_ROUTE:
 #   flags    - the launcher reads a flag file; write it there
 #   desktop  - no flag file; shadow or edit the desktop entry
@@ -24,7 +24,7 @@ MCA_ROUTES=()
 MCA_ROUTE=''
 
 mca_route() {
-	local kind="$1" id="$2" prog="$3"
+	local kind="$1" id="$2" prog="$3" packaging="${4:-native}"
 
 	if [[ $kind == steam ]]; then
 		if mca_config_list_has Skip "$id" || [[ $CFG_STEAM != yes ]]; then
@@ -35,14 +35,14 @@ mca_route() {
 		return
 	fi
 
-	if ! mca_kind_wanted "$kind" "$id"; then
+	if ! mca_kind_wanted "$kind" "$id" "$packaging"; then
 		[[ $kind == unknown ]] && MCA_ROUTE=unknown || MCA_ROUTE=off
 		return
 	fi
 
-	# A Flatpak has its own copy of everything and none of the host's wrappers,
+	# A Flatpak or a snap carries its own copy of everything and sees none of
-	# so the desktop entry is the only way in.
+	# the host's wrappers, so the desktop entry is the only way in.
-	if [[ $kind == flatpak ]]; then
+	if [[ $packaging != native ]]; then
 		MCA_ROUTE=desktop
 		return
 	fi
@@ -59,13 +59,22 @@ mca_route() {
 # as it likes to be - it writes only what differs, which is what keeps the
 # watcher from chasing its own changes.
 mca_apply() {
-	local i id file prog kind route steam_done=0
+	local i id file prog kind packaging route steam_done=0
 
 	MCA_CHANGES=0
 	MCA_ROUTES=()
 	MCA_N_ON=0; MCA_N_OFF=0; MCA_N_UNKNOWN=0
 
 	mca_config_load
+
+	# An installation that was set up by a version whose answer was a different
+	# flag still has that flag where it put it, and nothing below would touch it
+	# again: a file that is already marked as patched is left alone. Taking
+	# everything back once, here, is what carries such an installation over.
+	if [[ "$(mca_state_read flag_scheme 1)" != "$MCA_FLAG_SCHEME" ]]; then
+		mca_revert_all
+	fi
+
 	mca_scan
 
 	for i in "${!MCA_IDS[@]}"; do
@@ -73,8 +82,9 @@ mca_apply() {
 		file="${MCA_FILES[i]}"
 		prog="${MCA_PROGS[i]}"
 		kind="${MCA_KINDS[i]}"
+		packaging="${MCA_PACKAGING[i]}"
 
-		mca_route "$kind" "$id" "$prog"
+		mca_route "$kind" "$id" "$prog" "$packaging"
 		route="$MCA_ROUTE"
 		MCA_ROUTES[i]="$route"
 
@@ -86,13 +96,16 @@ mca_apply() {
 
 		case "$route" in
 			flags)
-				mca_flags_apply "$prog" || mca_desktop_apply "$id" "$file"
+				mca_flags_apply "$prog" "$kind" \
+					|| mca_desktop_apply "$id" "$file" "$(mca_flags "$kind")"
 				;;
 			desktop)
-				mca_desktop_apply "$id" "$file"
+				mca_desktop_apply "$id" "$file" "$(mca_flags "$kind")"
 				;;
 			steam)
-				mca_steam_desktop_apply "$id" "$file"
+				# Nothing is done to the entry itself: what Steam needs is
+				# in its own installation, and the same patch serves every
+				# way of starting the client.
 				if (( ! steam_done )); then
 					mca_steam_apply
 					steam_done=1
@@ -107,14 +120,33 @@ mca_apply() {
 		mca_steam_apply
 	fi
 
-	[[ $CFG_AUTOSTART == yes ]] && mca_autostart_apply
+	# Autostart entries. A Chromium application that starts itself at login
+	# points straight at its binary and never reads the entry in the menu, so
+	# Discord at login used to behave differently from Discord from the menu.
+	if [[ $CFG_AUTOSTART == yes ]]; then
+		mca_autostart_apply
+	fi
+
+	# Shortcuts on the desktop itself, which nothing above has seen: the XDG
+	# search path does not go there. Each entry is gated on its own, so there is
+	# nothing to check out here.
+	mca_shortcuts_apply
+
 	[[ $CFG_SPOTIFY == yes ]] && mca_spotify_apply
 
+	# Not about any one application: middle click goes on pasting everywhere
+	# else on the desktop, and KDE is the one desktop that can be told not to.
+	# See kde.sh.
+	[[ $CFG_PASTE == yes ]] && mca_kde_paste_apply
+
+	mca_prune_orphans
+
 	if (( MCA_CHANGES )) && mca_have update-desktop-database; then
 		update-desktop-database "$MCA_APPDIR" 2>/dev/null || true
 	fi
 
 	mca_state_write last_apply "$(date +%s)"
+	mca_state_write flag_scheme "$MCA_FLAG_SCHEME"
 	return 0
 }
 
@@ -135,13 +167,19 @@ mca_revert() {
 # The watcher
 # ---------------------------------------------------------------------------
 # A systemd user path unit watching every directory a desktop entry can appear
-# in. That covers a package installed with pacman, a Flatpak, an AppImage
+# in. That covers a package from whatever the distribution's package manager
-# registered by hand and a Steam client update, without a hook per package
+# is, a Flatpak, a snap, an AppImage registered by hand and a Steam client
-# manager.
+# update, without a hook per package manager.
 
 MCA_UNIT_PATH="middleclick-autoscroll.path"
 MCA_UNIT_SERVICE="middleclick-autoscroll.service"
 
+# The desktop folder is watched like every other directory an entry can turn up
+# in, but its name is translated and the unit that ships with the package
+# cannot know it. So that one path is written here, into a drop-in, from the
+# name this system actually uses.
+MCA_UNIT_DROPIN="${MCA_XDG_CONFIG}/systemd/user/${MCA_UNIT_PATH}.d"
+
 mca_watch_available() {
 	mca_have systemctl && [[ -n ${XDG_RUNTIME_DIR:-} || -S "/run/user/$(id -u)/bus" ]]
 }
@@ -151,17 +189,56 @@ mca_watch_enabled() {
 	systemctl --user is-enabled --quiet "$MCA_UNIT_PATH" 2>/dev/null
 }
 
+# _mca_watch_dropin_write
+# Returns 0 when the drop-in changed and systemd has to be told, 1 when it was
+# already right - the same contract as mca_write_if_changed, and for the same
+# reason: the watcher runs after every desktop entry that appears anywhere on
+# the system, and a daemon-reload each time would be absurd.
+_mca_watch_dropin_write() {
+	local dir file="$MCA_UNIT_DROPIN/desktop.conf" content
+
+	dir="$(mca_desktop_folder)"
+	[[ -d $dir ]] || { _mca_watch_dropin_remove; return $?; }
+
+	# A per cent sign starts a specifier in a unit file and has to be doubled
+	# to mean itself. Rare in a folder name, fatal when it happens.
+	content="[Path]"$'\n'"PathModified=${dir//%/%%}"$'\n'
+
+	mca_write_if_changed "$file" "$content"
+}
+
+_mca_watch_dropin_remove() {
+	[[ -e "$MCA_UNIT_DROPIN/desktop.conf" ]] || return 1
+	rm -f -- "$MCA_UNIT_DROPIN/desktop.conf"
+	rmdir "$MCA_UNIT_DROPIN" 2>/dev/null || true
+	return 0
+}
+
 mca_watch_enable() {
 	mca_watch_available || return 1
+	_mca_watch_dropin_write
+	systemctl --user daemon-reload > /dev/null 2>&1 || true
 	systemctl --user enable --now "$MCA_UNIT_PATH" > /dev/null 2>&1 || return 1
 	systemctl --user enable "$MCA_UNIT_SERVICE" > /dev/null 2>&1 || true
 	return 0
 }
 
+# mca_watch_refresh
+# Keeps a running watcher in step with a desktop folder that has been renamed,
+# which is what a change of session language does to it.
+mca_watch_refresh() {
+	mca_watch_available || return 0
+	_mca_watch_dropin_write || return 0
+	systemctl --user daemon-reload > /dev/null 2>&1 || true
+	systemctl --user restart "$MCA_UNIT_PATH" > /dev/null 2>&1 || true
+	return 0
+}
+
 mca_watch_disable() {
 	mca_watch_available || return 0
 	systemctl --user disable --now "$MCA_UNIT_PATH" > /dev/null 2>&1 || true
 	systemctl --user disable "$MCA_UNIT_SERVICE" > /dev/null 2>&1 || true
+	_mca_watch_dropin_remove && systemctl --user daemon-reload > /dev/null 2>&1
 	return 0
 }
 
@@ -183,7 +260,8 @@ mca_count_routes() {
 	MCA_ROUTES=()
 
 	for i in "${!MCA_IDS[@]}"; do
-		mca_route "${MCA_KINDS[i]}" "${MCA_IDS[i]}" "${MCA_PROGS[i]}"
+		mca_route "${MCA_KINDS[i]}" "${MCA_IDS[i]}" "${MCA_PROGS[i]}" \
+			"${MCA_PACKAGING[i]}"
 		route="$MCA_ROUTE"
 		MCA_ROUTES[i]="$route"
 		case "$route" in

src/lib/common.sh

@@ -13,11 +13,46 @@ MCA_PRETTY="Middle-Click Autoscroll"
 # The whole point of the package. Blink implements Windows-style autoscroll
 # behind a runtime flag that Chromium does not turn on for Linux, because
 # middle click is taken by primary-selection paste there.
+#
+# There are two ways to ask for that flag, and which one is right depends on
+# what is being started:
+#
+#   --enable-blink-features=MiddleClickAutoscroll is the one that works
+#   everywhere, and the only one that works in the Chromium versions embedded
+#   applications ship - Steam's CEF, an Electron a few years old, anything
+#   before Chromium 124. A browser started with it puts a yellow bar above the
+#   page saying an unsupported command line flag is in use, because Chromium
+#   keeps a list of flags worth warning about and this is on it.
+#
+#   --enable-features=MiddleClickAutoscroll is not on that list, so a browser
+#   started with it says nothing. Blink generates a feature of the same name
+#   for every one of its runtime flags, which is what makes the two the same
+#   request - but only since Chromium 124. Before that the name means nothing
+#   and is ignored without a word.
+#
+# So a browser, which is the only thing that shows the bar and the one thing
+# that keeps itself up to date, is given the quiet one; everything else keeps
+# the one that always works.
 MCA_FLAG="--enable-blink-features=MiddleClickAutoscroll"
 
-# The Blink feature name on its own, for merging into an --enable-blink-features
+# Helium ships the feature under its own name and does not answer to the
-# list that an app (or the user) already carries.
+# Chromium one, so browsers are asked for both. A name a browser does not know
+# is ignored, which is what makes one list safe to hand to all of them.
+MCA_BROWSER_FLAG="--enable-features=MiddleClickAutoscroll,HeliumMiddleClickAutoscroll"
+
+# The feature names on their own, for merging into a list that an application
+# (or the user) already carries, and for taking them back out again.
 MCA_FEATURE="MiddleClickAutoscroll"
+MCA_BROWSER_FEATURES="MiddleClickAutoscroll,HeliumMiddleClickAutoscroll"
+
+# Bumped when the flags above change, and when what gets written where does.
+# An installation that was set up by a version with a different answer is taken
+# back and done again once, because a file that is already patched is otherwise
+# left alone. See mca_apply.
+#
+# 3 is what takes -noverifyfiles back out of the Steam entries an older version
+# put it in.
+MCA_FLAG_SCHEME=3
 
 MCA_LIBDIR="${MCA_LIBDIR:-@LIBDIR@}"
 MCA_LOCALEDIR="${MCA_LOCALEDIR:-@LOCALEDIR@}"
@@ -34,7 +69,7 @@ MCA_CACHEDIR="${MCA_CACHEDIR:-${MCA_XDG_CACHE}/${MCA_NAME}}"
 
 # Where generated desktop entries go. A file here shadows the one with the same
 # name in /usr/share/applications, which is how an application gets extra
-# command line arguments without touching anything pacman owns.
+# command line arguments without touching a file the package manager owns.
 MCA_APPDIR="${MCA_XDG_DATA}/applications"
 
 # Copies of every file that is edited in place rather than shadowed.
@@ -44,6 +79,29 @@ MCA_BACKUPDIR="${MCA_STATEDIR}/backup"
 # else. See mca_ledger_add.
 MCA_LEDGER="${MCA_STATEDIR}/ledger"
 
+# The folder the desktop itself shows. Nothing in the XDG search path looks at
+# it, so an entry that lives only there is invisible to a scan - and a game
+# shortcut dragged onto the desktop is exactly that.
+#
+# Its name is translated: Schreibtisch, Bureau, Escritorio. The name in use is
+# in the file xdg-user-dirs writes, so it is read rather than guessed, and
+# ~/Desktop is only the fallback for a system that has no such file.
+mca_desktop_folder() {
+	local file="$MCA_XDG_CONFIG/user-dirs.dirs" line dir=''
+
+	if [[ -r $file ]]; then
+		while IFS= read -r line; do
+			[[ $line == XDG_DESKTOP_DIR=* ]] || continue
+			dir="${line#XDG_DESKTOP_DIR=}"
+			dir="${dir%\"}"; dir="${dir#\"}"
+		done < "$file"
+		dir="${dir/#\$HOME/$HOME}"
+	fi
+
+	[[ $dir == /* ]] || dir="$HOME/Desktop"
+	printf '%s\n' "${dir%/}"
+}
+
 # ---------------------------------------------------------------------------
 # Translations
 # ---------------------------------------------------------------------------
@@ -60,8 +118,15 @@ mca_ui_locale() {
 		[[ -z $l ]] && l="${LANG:-}"
 	fi
 
-	if [[ -z $l && -r /etc/locale.conf ]]; then
+	# systemd writes /etc/locale.conf and most distributions use it; Debian and
-		l="$(sed -n 's/^LANG=//p' /etc/locale.conf | tr -d '"' | head -n1)"
+	# Ubuntu keep the same LANG= line in /etc/default/locale instead.
+	if [[ -z $l ]]; then
+		local f
+		for f in /etc/locale.conf /etc/default/locale; do
+			[[ -r $f ]] || continue
+			l="$(sed -n 's/^LANG=//p' "$f" | tr -d '"' | head -n1)"
+			[[ -n $l ]] && break
+		done
 	fi
 
 	printf '%s\n' "${l:-C}"
@@ -213,9 +278,12 @@ mca_state_write() {
 #   shadow  <generated desktop entry>   <source entry it was generated from>
 #   inplace <edited file>               <basename of its backup copy>
 #   flags   <flag file>                 created | appended | merged
+#   kwin    <kwinrc>                    what EnablePrimarySelection said before
 #
-# `inplace` and `flags` differ in how they are undone: a backup is restored
+# The kinds differ in how they are undone: a backup is restored wholesale, a
-# wholesale, a flag file only loses the one line that was added to it.
+# flag file only loses the one line that was added to it, and kwinrc gets one
+# key written back - it is a file KDE writes to itself, and putting a whole
+# copy of it back would take everything else settled since with it.
 
 mca_ledger_add() {
 	local kind="$1" path="$2" detail="${3:-}"
@@ -228,6 +296,25 @@ mca_ledger_add() {
 	printf '%s\t%s\t%s\n' "$kind" "$path" "$detail" >> "$MCA_LEDGER"
 }
 
+# mca_ledger_has <path>
+# Whether the ledger still knows about that file. Worth asking because the copy
+# kept beside it is named after the path and outlives a ledger that was lost or
+# truncated: a file nothing has a record of any more is one nothing would ever
+# look at again.
+mca_ledger_has() {
+	[[ -f $MCA_LEDGER ]] || return 1
+	awk -F'\t' -v p="$1" '$2 == p { found = 1 } END { exit !found }' "$MCA_LEDGER"
+}
+
+# mca_ledger_detail <path>
+# The third column of that file's line, empty when the ledger has none. What it
+# means is the kind's business; for `kwin` it is the value to put back.
+mca_ledger_detail() {
+	[[ -f $MCA_LEDGER ]] || return 1
+	awk -F'\t' -v p="$1" '$2 == p { d = $3 } END { if (!length(d)) exit 1; print d }' \
+		"$MCA_LEDGER"
+}
+
 mca_ledger_forget() {
 	local path="$1" tmp
 	[[ -f $MCA_LEDGER ]] || return 0
@@ -239,6 +326,14 @@ mca_ledger_forget() {
 }
 
 
+# mca_backup_name <file>
+# The name a backup copy of that file is stored under. Derived from the path
+# rather than remembered, so a caller can ask whether a file has been backed up
+# before without reading the ledger.
+mca_backup_name() {
+	printf '%s' "$1" | sed 's|/|%|g'
+}
+
 # mca_backup <file>
 # Copies a file aside before it is edited in place, and prints the name the
 # copy was stored under. Existing backups are never overwritten: the first copy
@@ -246,7 +341,7 @@ mca_ledger_forget() {
 # patched version.
 mca_backup() {
 	local file="$1" name
-	name="$(printf '%s' "$file" | sed 's|/|%|g')"
+	name="$(mca_backup_name "$file")"
 
 	mkdir -p "$MCA_BACKUPDIR" 2>/dev/null || return 1
 	if [[ ! -e "$MCA_BACKUPDIR/$name" ]]; then

src/lib/config.sh

@@ -139,10 +139,12 @@ mca_config_load() {
 	CFG_APPS=no;       mca_config_bool PatchApps        yes && CFG_APPS=yes
 	CFG_BROWSERS=no;   mca_config_bool PatchBrowsers    yes && CFG_BROWSERS=yes
 	CFG_FLATPAK=no;    mca_config_bool PatchFlatpak     yes && CFG_FLATPAK=yes
+	CFG_SNAP=no;       mca_config_bool PatchSnap        yes && CFG_SNAP=yes
 	CFG_AUTOSTART=no;  mca_config_bool PatchAutostart   yes && CFG_AUTOSTART=yes
 	CFG_STEAM=no;      mca_config_bool PatchSteam       yes && CFG_STEAM=yes
 	CFG_SPOTIFY=no;    mca_config_bool PatchSpotify     yes && CFG_SPOTIFY=yes
 	CFG_WATCH=no;      mca_config_bool WatchNewApps     yes && CFG_WATCH=yes
+	CFG_PASTE=no;      mca_config_bool DisablePaste     yes && CFG_PASTE=yes
 
 	CFG_EXTRA_FLAGS="$(mca_config_get ExtraFlags '')"
 
@@ -153,10 +155,18 @@ mca_config_load() {
 	CFG_SKIP="$(mca_config_get Skip '')"
 }
 
+# mca_flags [kind]
 # The full argument string that gets injected. Kept in one place so the flag
 # file writer and the desktop entry writer cannot drift apart.
+#
+# A browser gets the flag that leaves it without a warning bar; everything else
+# gets the one that works in every Chromium there is. See MCA_FLAG.
 mca_flags() {
+	if [[ ${1:-app} == browser ]]; then
+		printf '%s' "$MCA_BROWSER_FLAG"
+	else
 		printf '%s' "$MCA_FLAG"
+	fi
 	[[ -n ${CFG_EXTRA_FLAGS:-} ]] && printf ' %s' "$CFG_EXTRA_FLAGS"
 	printf '\n'
 }

src/lib/detect.sh

@@ -27,9 +27,23 @@ MCA_MARKERS=(
 MCA_SYSTEM_DIRS=(
 	/ /bin /lib /lib32 /lib64 /sbin /usr /usr/bin /usr/lib /usr/lib32
 	/usr/lib64 /usr/libexec /usr/sbin /usr/local /usr/local/bin
-	/usr/local/lib /opt
+	/usr/local/lib /usr/local/libexec /opt
 )
 
+# The same thing for the layouts that put a machine triplet in the path.
+# Debian and Ubuntu keep the shared libraries in /usr/lib/x86_64-linux-gnu
+# rather than /usr/lib, so that directory is every bit as shared as /usr/lib is
+# elsewhere and a marker sitting in it belongs to nobody in particular.
+MCA_SYSTEM_DIR_GLOBS=(
+	'/usr/lib/*-linux-gnu*' '/usr/lib32/*-linux-gnu*'
+	'/usr/lib64/*-linux-gnu*' '/usr/local/lib/*-linux-gnu*'
+)
+
+# Where snapd mounts the installed snaps. /snap is the usual place and the one
+# the shims point into; distributions that keep /snap free of a top-level
+# directory use the second.
+MCA_SNAP_DIRS=(/snap /var/lib/snapd/snap)
+
 # Strings in a launcher script that mean it starts a Chromium or Electron
 # process, for the wrappers whose command line is assembled out of variables and
 # cannot be followed from the outside.
@@ -38,34 +52,51 @@ MCA_SYSTEM_DIRS=(
 # "chromium" on its own is not one of them: /usr/bin/xdg-open lists every
 # browser it knows how to start, and that is not a browser.
 #
-# The flag file convention is an Arch packaging habit and says nothing about the
+# The flag file convention is one distribution's packaging habit and says
-# engine either, so it is not in here.
+# nothing about the engine either, so it is not in here.
-MCA_SCRIPT_HINTS='ELECTRON_|app\.asar|chrome-sandbox|libcef|enable-blink-features|ozone-platform-hint'
+#
+# CHROMIUM_FLAGS and CHROME_WRAPPER earn their place: they are the variables
+# the Debian, Fedora and openSUSE Chromium wrappers and Google's own Chrome
+# wrapper build their command line out of, and nothing else sets them.
+MCA_SCRIPT_HINTS='ELECTRON_|app\.asar|chrome-sandbox|libcef|enable-blink-features|ozone-platform-hint|CHROMIUM_FLAGS|CHROME_WRAPPER|CHROME_VERSION_EXTRA'
 
 # ---------------------------------------------------------------------------
 # Desktop entries
 # ---------------------------------------------------------------------------
 
+# Where Flatpak and snapd put the launchers they export. Both add these to
+# XDG_DATA_DIRS themselves, through a file in /etc/profile.d - but only for a
+# session that was started after they were installed, and only for a session
+# manager that reads it at all. They are appended, after everything XDG names,
+# so a directory that is already in the search path keeps its own position and
+# the ones that were missing are still scanned.
+mca_extra_desktop_dirs() {
+	printf '%s\n' \
+		"$MCA_XDG_DATA/flatpak/exports/share/applications" \
+		/var/lib/flatpak/exports/share/applications \
+		/var/lib/snapd/desktop/applications
+}
+
 # The directories a desktop entry can come from, most specific first - which is
 # also XDG lookup order, so the first file found for an id is the one that is
 # actually used.
 mca_desktop_dirs() {
 	local dirs="${XDG_DATA_DIRS:-/usr/local/share:/usr/share}" d
+	local -A seen=()
+
+	while IFS= read -r d; do
+		[[ -n $d ]] || continue
+		d="${d%/}"
+		[[ -n ${seen[$d]+set} ]] && continue
+		seen[$d]=1
+		printf '%s\n' "$d"
+	done < <(
 		printf '%s\n' "$MCA_APPDIR"
 		while IFS= read -r -d: d; do
 			[[ -n $d ]] && printf '%s/applications\n' "${d%/}"
 		done <<< "${dirs}:"
-}
+		mca_extra_desktop_dirs
-
+	)
-# mca_desktop_get <file> <key>
-# A single value from the [Desktop Entry] group. Desktop Action groups repeat
-# the same keys, and reading past the first group would pick up the wrong one.
-mca_desktop_get() {
-	local file="$1" key="$2"
-	awk -v key="$key" '
-		/^[[:space:]]*\[/ { inentry = ($0 ~ /^[[:space:]]*\[Desktop Entry\][[:space:]]*$/); next }
-		inentry && index($0, key "=") == 1 { print substr($0, length(key) + 2); exit }
-	' "$file" 2>/dev/null
 }
 
 # _mca_desktop_read <file>
@@ -180,6 +211,74 @@ mca_exec_flatpak_id() {
 	return 1
 }
 
+# mca_exec_is_steam_link <exec line> <program>
+# Whether an entry starts something inside Steam rather than starting Steam
+# itself: it carries a steam:// address of its own. Steam writes one of those
+# for every game somebody asks for a shortcut to, and the client's own entry
+# never has one - it takes an address from the outside, through %U.
+mca_exec_is_steam_link() {
+	local line="$1" prog="$2"
+
+	[[ $line == *steam://* ]] || return 1
+	mca_prog_is_steam "$prog"
+}
+
+# _mca_prog_is_steam_name <program>
+# The launcher under one of the names Valve and the distributions give it.
+_mca_prog_is_steam_name() {
+	case "${1##*/}" in
+		steam|steam-runtime|steam-native|steam-jupiter) return 0 ;;
+	esac
+	return 1
+}
+
+# _mca_prog_is_steam_wrapper <program>
+# Whether a script in front of the client is a way of starting Steam. People
+# put one there to add a switch of their own, and an entry pointing at it is a
+# Steam start like any other - but the script is not named after Steam, so
+# nothing above recognises it.
+#
+# Getting this wrong is worse than it sounds: such a script tends to mention
+# the flag it is there to add, which is one of the markers that say "Chromium"
+# to the hint scan. The entry then ends up being handled as an application and
+# is given the flag on its command line, where Steam ignores it, instead of
+# being handed to the Steam module that knows how to reach the web helper.
+#
+# Only the handover is followed, and only one step of it: the client's own
+# launcher is already recognised by name, so a wrapper in front of it is the
+# whole of what is left.
+_mca_prog_is_steam_wrapper() {
+	local prog="$1" head='' target
+
+	[[ $prog == /* && -f $prog && -r $prog ]] || return 1
+
+	# Two characters, read in the shell: the scan asks this about every program
+	# on the system, and most of them are binaries whose first line is the whole
+	# file.
+	read -r -N 2 head < "$prog" 2>/dev/null || return 1
+	[[ $head == '#!' ]] || return 1
+
+	target="$(_mca_script_target "$prog")" || return 1
+	[[ -n $target ]] || return 1
+	_mca_prog_is_steam_name "$target"
+}
+
+# mca_prog_is_steam <program>
+# Whether running this program starts the Steam client. Every packaging is in
+# here and every name Valve and the distributions give the launcher, because
+# the answer decides whether an entry gets Steam's own switch - and an entry
+# that starts Steam without it undoes the web helper patch on the way up.
+#
+# The program is what a scan leaves behind: an absolute path for a native
+# install, flatpak:<id> or snap:<name> for the other two.
+mca_prog_is_steam() {
+	local prog="$1"
+
+	_mca_prog_is_steam_name "$prog" && return 0
+	[[ $prog == flatpak:com.valvesoftware.Steam || $prog == snap:steam ]] && return 0
+	_mca_prog_is_steam_wrapper "$prog"
+}
+
 # ---------------------------------------------------------------------------
 # Is this Chromium?
 # ---------------------------------------------------------------------------
@@ -250,6 +349,11 @@ _mca_has_markers() {
 	for s in "${MCA_SYSTEM_DIRS[@]}"; do
 		[[ $dir == "$s" ]] && return 1
 	done
+	for s in "${MCA_SYSTEM_DIR_GLOBS[@]}"; do
+		# Unquoted on purpose - these are patterns, not names.
+		# shellcheck disable=SC2053
+		[[ $dir == $s ]] && return 1
+	done
 
 	for m in "${MCA_MARKERS[@]}"; do
 		[[ -e "$dir/$m" ]] && return 0
@@ -258,23 +362,118 @@ _mca_has_markers() {
 	return 1
 }
 
+# The plain assignments the script made before it handed over, for
+# _mca_script_subst to read. A variable of its own rather than something passed
+# around: every caller of _mca_script_target reads it through a command
+# substitution, so each call already works on a copy and there is nothing here
+# that two of them could collide over.
+declare -A MCA_SCRIPT_VARS=()
+
+# _mca_script_subst <text>
+# The text with $NAME and ${NAME} replaced by what the script assigned to them,
+# left in MCA_SUBST.
+#
+# Fails as soon as something turns up that only a running shell could work out
+# - a positional parameter, a name the script never set, a default value. That
+# is the point: an unresolvable path has to come out as no path at all, never
+# as a wrong one.
+MCA_SUBST=''
+
+_mca_script_subst() {
+	local text="$1" out='' rest name
+
+	while [[ $text == *'$'* ]]; do
+		out+="${text%%\$*}"
+		rest="${text#*\$}"
+
+		if [[ $rest == '{'* ]]; then
+			[[ $rest == *'}'* ]] || return 1
+			name="${rest%%\}*}"; name="${name#\{}"
+			rest="${rest#*\}}"
+		else
+			name="${rest%%[!A-Za-z0-9_]*}"
+			rest="${rest:${#name}}"
+		fi
+
+		[[ $name =~ ^[A-Za-z_][A-Za-z0-9_]*$ ]] || return 1
+		[[ -n ${MCA_SCRIPT_VARS[$name]+set} ]] || return 1
+
+		out+="${MCA_SCRIPT_VARS[$name]}"
+		text="$rest"
+	done
+
+	MCA_SUBST="$out$text"
+	return 0
+}
+
 # _mca_script_target <script>
 # The program a wrapper script hands over to, so a chain like
 # heroic -> electron43 -> /usr/lib/electron43/electron can be followed.
+#
+# The assignments above the exec line are followed as well, because that is the
+# shape the Chromium wrappers outside Arch have: Debian, Ubuntu, Fedora and
+# openSUSE all set the directory and the program name into variables at the top
+# of the script and end on `exec -a "$APPNAME" "$LIBDIR/$APPNAME"`. Without
+# resolving those there is nothing to follow, and the answer would have to come
+# from the hint scan - a weaker kind of evidence than finding the binary and
+# its markers.
 _mca_script_target() {
-	local script="$1" line tok
+	local script="$1" line tok name val skip=0
 	local -a tokens
+	local re_assign='^[[:space:]]*(export[[:space:]]+)?([A-Za-z_][A-Za-z0-9_]*)=([^[:space:];|&()`]*)[[:space:]]*$'
+
+	MCA_SCRIPT_VARS=()
 
 	while IFS= read -r line; do
+		if [[ $line =~ $re_assign ]]; then
+			name="${BASH_REMATCH[2]}"
+			val="${BASH_REMATCH[3]}"
+
+			# One pair of quotes around the whole value is ordinary and means
+			# nothing here. Single quotes also mean the value is literal, so
+			# there is nothing left to expand.
+			if [[ $val == \'*\' ]]; then
+				MCA_SCRIPT_VARS[$name]="${val:1:${#val}-2}"
+				continue
+			fi
+			[[ $val == \"*\" ]] && val="${val:1:${#val}-2}"
+
+			if _mca_script_subst "$val"; then
+				MCA_SCRIPT_VARS[$name]="$MCA_SUBST"
+			else
+				# Not resolvable, so anything built from it must not be either.
+				unset "MCA_SCRIPT_VARS[$name]"
+			fi
+			continue
+		fi
+
 		[[ $line =~ ^[[:space:]]*exec[[:space:]]+(.*)$ ]] || continue
 		read -r -a tokens <<< "${BASH_REMATCH[1]}"
+		skip=0
 		for tok in "${tokens[@]}"; do
-			[[ $tok == env ]] && continue
+			(( skip )) && { skip=0; continue; }
+			case "$tok" in
+				env) continue ;;
+				# `exec -a NAME PROG` renames the process. NAME is not a
+				# program, and it is usually the wrapper's own name, so
+				# following it would lead straight back here.
+				-a|--argv0) skip=1; continue ;;
+				-*) continue ;;
+			esac
 			[[ $tok == *=* && $tok != /* ]] && continue
-			[[ $tok == -* ]] && continue
+
-			# Anything still carrying a shell variable cannot be resolved from
+			tok="${tok%\"}"; tok="${tok#\"}"
-			# the outside; the hint scan has to answer for those.
+			tok="${tok%\'}"; tok="${tok#\'}"
-			[[ $tok == *'$'* ]] && return 1
+
+			# Anything still carrying a shell variable is resolved from the
+			# assignments above, or not at all; the hint scan answers for the
+			# wrappers that build their command line some other way.
+			if [[ $tok == *'$'* ]]; then
+				_mca_script_subst "$tok" || return 1
+				tok="$MCA_SUBST"
+			fi
+			[[ -n $tok ]] || return 1
+
 			if [[ $tok == /* ]]; then
 				printf '%s\n' "$tok"
 			else
@@ -287,13 +486,15 @@ _mca_script_target() {
 }
 
 # mca_flags_candidates <program>
-# The flag files a launcher reads, in the order it reads them. Arch's Electron
+# The flag files a launcher reads, in the order it reads them, taken from the
-# and Chromium wrappers all take extra arguments from
+# launcher itself rather than assumed from the distribution. Where the wrappers
-# $XDG_CONFIG_HOME/<name>-flags.conf, which is a far better place to inject than
+# follow that convention - Arch's Electron and Chromium packages do, and take
-# a desktop entry: it survives package updates and it applies to a launch from
+# extra arguments from $XDG_CONFIG_HOME/<name>-flags.conf - it is a far better
-# the terminal too.
+# place to inject than a desktop entry: it survives package updates and it
+# applies to a launch from the terminal too. Where they do not, this finds
+# nothing and the caller falls back to the desktop entry.
 mca_flags_candidates() {
-	local prog="$1" depth="${2:-0}" target
+	local prog="$1" depth="${2:-0}" target inherited
 	(( depth > 3 )) && return 0
 	[[ -r $prog ]] || return 0
 	head -c2 -- "$prog" 2>/dev/null | grep -q '#!' || return 0
@@ -301,10 +502,22 @@ mca_flags_candidates() {
 	grep -oE '[A-Za-z0-9_.+-]+-flags\.conf' -- "$prog" 2>/dev/null
 
 	# A wrapper that only execs another wrapper (heroic -> electron43) inherits
-	# that one's flag files, plus the specific name it builds from a variable.
+	# that one's flag files, plus the specific name it builds from a variable
+	# at runtime and therefore never writes down - which is why that one is
+	# derived from the target's own name rather than found.
+	#
+	# It is derived only once the target has shown that it reads a flag file at
+	# all. Every launcher that can be followed is not a launcher that reads
+	# one: the Chromium wrappers outside Arch do not, and neither does an
+	# ordinary program that simply execs its own binary. Naming a file for
+	# those would put the flag somewhere nothing ever looks and skip the
+	# desktop entry that would have worked.
 	if target="$(_mca_script_target "$prog")" && [[ -n $target ]]; then
+		inherited="$(mca_flags_candidates "$target" $(( depth + 1 )))"
+		if [[ -n $inherited ]]; then
 			printf '%s-flags.conf\n' "${target##*/}"
-		mca_flags_candidates "$target" $(( depth + 1 ))
+			printf '%s\n' "$inherited"
+		fi
 	fi
 }
 
@@ -398,8 +611,9 @@ _mca_detect_uncached() {
 MCA_IDS=()        # desktop file id, without the .desktop suffix
 MCA_FILES=()      # the desktop entry that is in effect for that id
 MCA_NAMES=()      # display name
-MCA_PROGS=()      # resolved program, or a flatpak app id
+MCA_PROGS=()      # resolved program, or a Flatpak app id or a snap name
-MCA_KINDS=()      # app | browser | flatpak | steam | unknown | no
+MCA_KINDS=()      # app | browser | steam | unknown | no
+MCA_PACKAGING=()  # native | flatpak | snap
 
 # A scan reads every desktop entry on the system, so the menu does it once and
 # then redraws from what it found. Applying rescans on its own, so nothing else
@@ -412,11 +626,12 @@ mca_scan_once() {
 }
 
 mca_scan() {
-	local dir file id name exec_line prog kind i
+	local dir file id name exec_line prog kind packaging i
 	local -A seen=()
 	local -a c_ids=() c_files=() c_names=() c_progs=() c_browser=() c_stat=()
 
 	MCA_IDS=(); MCA_FILES=(); MCA_NAMES=(); MCA_PROGS=(); MCA_KINDS=()
+	MCA_PACKAGING=()
 
 	# Pass one: read the entries and work out what each of them starts. No
 	# detection yet - that needs a stat per program, and those are collected so
@@ -452,8 +667,17 @@ mca_scan() {
 			if [[ ${prog##*/} == flatpak ]]; then
 				mca_exec_flatpak_id "$exec_line" || continue
 				prog="flatpak:$MCA_PROG"
+			elif mca_snap_name "$prog"; then
+				prog="snap:$MCA_PROG"
 			fi
 
+			# The shortcuts Steam writes for single games are not
+			# applications of their own - a game is whatever engine it was
+			# built with, and none of those reads a Chromium argument - and
+			# starting the client through one needs nothing on its command
+			# line either.
+			mca_exec_is_steam_link "$exec_line" "$prog" && continue
+
 			c_ids+=("$id"); c_files+=("$file"); c_names+=("$name")
 			c_progs+=("$prog")
 			if mca_desktop_is_browser; then c_browser+=(1); else c_browser+=(0); fi
@@ -464,15 +688,32 @@ mca_scan() {
 	MCA_STAT=()
 	_mca_stat_batch "${c_stat[@]}"
 
-	# Pass two: decide what each one is.
+	# Pass two: decide what each one is. What it does - an application or a
+	# browser - and how it was packaged are two separate questions: a Chromium
+	# installed as a snap is still a browser, and somebody who has turned
+	# browsers off means that one too.
 	for i in "${!c_ids[@]}"; do
 		prog="${c_progs[i]}"
 		kind=no
+		packaging=native
 
 		if [[ $prog == flatpak:* ]]; then
+			packaging=flatpak
+			if mca_prog_is_steam "$prog"; then
+				kind=steam
+			elif mca_flatpak_is_chromium "${prog#flatpak:}"; then
+				(( c_browser[i] )) && kind=browser || kind=app
+			fi
 			prog="${prog#flatpak:}"
-			mca_flatpak_is_chromium "$prog" && kind=flatpak
+		elif [[ $prog == snap:* ]]; then
-		elif [[ ${prog##*/} == steam || ${prog##*/} == steam-runtime ]]; then
+			prog="${prog#snap:}"
+			packaging=snap
+			if [[ $prog == steam ]]; then
+				kind=steam
+			elif mca_snap_is_chromium "$prog"; then
+				(( c_browser[i] )) && kind=browser || kind=app
+			fi
+		elif mca_prog_is_steam "$prog"; then
 			# Steam is Chromium inside, but nothing about it can be changed
 			# from a command line argument; it has its own module.
 			kind=steam
@@ -489,6 +730,7 @@ mca_scan() {
 		MCA_NAMES+=("${c_names[i]}")
 		MCA_PROGS+=("$prog")
 		MCA_KINDS+=("$kind")
+		MCA_PACKAGING+=("$packaging")
 	done
 
 	mca_cache_flush
@@ -527,6 +769,66 @@ mca_desktop_is_browser() {
 	return 1
 }
 
+# mca_snap_name <program>
+# The snap an executable belongs to, left in MCA_PROG - assigned rather than
+# printed for the same reason mca_exec_program is: the scan asks this about
+# every desktop entry on the system, and a command substitution per entry is a
+# fork per entry.
+#
+# /snap/bin/<name> is the shim snapd puts in PATH and is a symlink to snapd
+# itself, so following it lands on /usr/bin/snap and says nothing whatever
+# about the application. The name is the only thing that carries information,
+# and it is what leads to the mounted tree below.
+mca_snap_name() {
+	local prog="$1" rest d
+
+	for d in "${MCA_SNAP_DIRS[@]}"; do
+		if [[ $prog == "$d/bin/"* ]]; then
+			rest="${prog#"$d/bin/"}"
+			# A snap that ships several programs names them <snap>.<app>.
+			MCA_PROG="${rest%%.*}"
+			return 0
+		fi
+		if [[ $prog == "$d/"* ]]; then
+			rest="${prog#"$d/"}"
+			MCA_PROG="${rest%%/*}"
+			return 0
+		fi
+	done
+	return 1
+}
+
+# mca_snap_is_chromium <snap name>
+# A snap keeps everything it ships inside its own mounted revision, so the
+# marker check works the same way there as anywhere else once that tree has
+# been located. "current" is the symlink snapd keeps pointing at the revision
+# that will actually be started.
+mca_snap_is_chromium() {
+	local name="$1" d root
+
+	if [[ -n ${MCA_DETECT_MEMO[snap:$name]+set} ]]; then
+		[[ ${MCA_DETECT_MEMO[snap:$name]} == yes ]]
+		return $?
+	fi
+
+	for d in "${MCA_SNAP_DIRS[@]}"; do
+		root="$d/$name/current"
+		[[ -d $root ]] || continue
+		if [[ -n "$(find "$root" -maxdepth 5 \
+			\( -name 'chrome_crashpad_handler' -o -name 'app.asar' \
+			   -o -name 'libcef.so' -o -name 'v8_context_snapshot.bin' \
+			   -o -name 'chrome-sandbox' \) \
+			-print -quit 2>/dev/null)" ]]
+		then
+			MCA_DETECT_MEMO[snap:$name]=yes
+			return 0
+		fi
+	done
+
+	MCA_DETECT_MEMO[snap:$name]=no
+	return 1
+}
+
 # mca_flatpak_is_chromium <app id>
 # Flatpak keeps every application in its own tree, so the marker check works the
 # same way once that tree has been located.
@@ -554,19 +856,28 @@ mca_flatpak_is_chromium() {
 	return 1
 }
 
-# mca_kind_wanted <kind> <id>
+# mca_kind_wanted <kind> <id> [packaging]
 # Whether the current settings say this entry should be patched. Skip beats
 # everything, an explicit include beats detection, and detection beats nothing.
+#
+# Packaging is a gate in front of the category rather than a category of its
+# own: a Flatpak or a snap sees none of the host's configuration and is worth
+# switching off as a group, but it is still an application or a browser and
+# whichever of those the user turned off applies to it too.
 mca_kind_wanted() {
-	local kind="$1" id="$2"
+	local kind="$1" id="$2" packaging="${3:-native}"
 
 	mca_config_list_has Skip "$id" && return 1
 	mca_config_list_has Include "$id" && return 0
 
+	case "$packaging" in
+		flatpak) [[ $CFG_FLATPAK == yes ]] || return 1 ;;
+		snap)    [[ $CFG_SNAP == yes ]] || return 1 ;;
+	esac
+
 	case "$kind" in
 		app)     [[ $CFG_APPS == yes ]] ;;
 		browser) [[ $CFG_BROWSERS == yes ]] ;;
-		flatpak) [[ $CFG_FLATPAK == yes && $CFG_APPS == yes ]] ;;
 		*)       return 1 ;;
 	esac
 }

src/lib/kde.sh

@@ -0,0 +1,167 @@
+# shellcheck shell=bash
+#
+# KDE's middle-click paste.
+#
+# Inside a Chromium application the flag settles this on its own: with
+# autoscroll on, Blink stops pasting the primary selection on middle click,
+# because the button is doing something else now. Everywhere else on the
+# desktop middle click goes on pasting, which is the behaviour this whole
+# program exists to get away from - so the desktop's own switch for it is
+# turned off too.
+#
+# KWin has such a switch, and only for a Wayland session, where the paste is a
+# protocol the compositor either offers or does not:
+#
+#   ~/.config/kwinrc, [Wayland], EnablePrimarySelection=false
+#
+# On X11 there is nothing to switch. The primary selection is part of X itself
+# and every toolkit reaches for it on its own; no one place can say no.
+#
+# KWin reads the key once, while it starts, so what is written here is true
+# from the next login on rather than straight away.
+
+MCA_KWINRC="${MCA_XDG_CONFIG}/kwinrc"
+MCA_KWIN_GROUP="Wayland"
+MCA_KWIN_KEY="EnablePrimarySelection"
+
+# The kconfig command line tools, whichever generation this session has. They
+# are what System Settings writes kwinrc with, and worth the fork: the file has
+# a cascade behind it - /etc/xdg, the kdedefaults directory - and entries a
+# distribution can mark immutable, and an edit that reaches past all that with
+# sed writes something KDE goes on to ignore.
+MCA_KDE_TOOL=''
+MCA_KDE_TOOL_LOOKED=0
+
+_mca_kde_tool() {
+	local gen
+
+	if (( ! MCA_KDE_TOOL_LOOKED )); then
+		MCA_KDE_TOOL_LOOKED=1
+		for gen in 6 5; do
+			if mca_have "kreadconfig$gen" && mca_have "kwriteconfig$gen"; then
+				MCA_KDE_TOOL="$gen"
+				break
+			fi
+		done
+	fi
+
+	[[ -n $MCA_KDE_TOOL ]] || return 1
+	printf '%s\n' "$MCA_KDE_TOOL"
+}
+
+# mca_kde_session
+# Whether this is a KWin Wayland session.
+mca_kde_session() {
+	local desktop="${XDG_CURRENT_DESKTOP:-}"
+
+	# The watcher is a systemd service, and one started before the session
+	# imported its environment sees none of these variables. A running
+	# kwin_wayland answers both halves of the question at once, and is what
+	# such a run ends up going by.
+	if [[ -z $desktop && -z ${KDE_FULL_SESSION:-} ]]; then
+		mca_have pgrep || return 1
+		pgrep -u "$(id -u)" -x kwin_wayland > /dev/null 2>&1
+		return
+	fi
+
+	# XDG_CURRENT_DESKTOP is the one every desktop sets, and the one to go by
+	# wherever it is set; KDE_FULL_SESSION is what answers when it is not.
+	[[ -z $desktop || ${desktop^^} == *KDE* ]] || return 1
+
+	[[ ${XDG_SESSION_TYPE:-} == wayland || -n ${WAYLAND_DISPLAY:-} ]]
+}
+
+mca_kde_available() {
+	mca_kde_session && _mca_kde_tool > /dev/null
+}
+
+# mca_kde_read [file]
+# What the key says now, lowercased, empty when it is not set at all.
+mca_kde_read() {
+	local file="${1:-$MCA_KWINRC}" gen val
+	gen="$(_mca_kde_tool)" || return 1
+
+	# kreadconfig creates the file it is pointed at, and the status screen -
+	# which asks on every redraw - has no business writing anything. A file
+	# that is not there has no value in it to read anyway.
+	[[ -f $file ]] || return 0
+
+	val="$("kreadconfig$gen" --file "$file" --group "$MCA_KWIN_GROUP" \
+		--key "$MCA_KWIN_KEY" 2>/dev/null)"
+	printf '%s\n' "${val,,}"
+}
+
+# mca_kde_write [file] <value>
+# An empty value takes the key back out rather than writing nothing into it -
+# a key that is missing and a key that says nothing are not the same thing to
+# KDE, and only the first one is what an untouched kwinrc looks like.
+mca_kde_write() {
+	local file="$1" value="$2" gen
+	gen="$(_mca_kde_tool)" || return 1
+
+	if [[ -z $value ]]; then
+		"kwriteconfig$gen" --file "$file" --group "$MCA_KWIN_GROUP" \
+			--key "$MCA_KWIN_KEY" --delete 2>/dev/null
+	else
+		"kwriteconfig$gen" --file "$file" --group "$MCA_KWIN_GROUP" \
+			--key "$MCA_KWIN_KEY" "$value" 2>/dev/null
+	fi
+}
+
+# mca_kde_paste_apply
+# Turns the paste off, and remembers what the key said before so that undoing
+# puts that back rather than a guess.
+#
+# A key that already says false without the ledger knowing about it was set by
+# the user or by the distribution. That one is left alone and nothing is
+# recorded, so `disable` cannot switch a paste back on that this program never
+# switched off.
+mca_kde_paste_apply() {
+	local current previous changed=0
+
+	mca_kde_available || return 1
+	current="$(mca_kde_read)" || return 1
+
+	if mca_ledger_has "$MCA_KWINRC"; then
+		# Ours already. What goes back is the value recorded the first time
+		# round, not what reading the file now would say - that is false, and
+		# false is what is being undone.
+		previous="$(mca_ledger_detail "$MCA_KWINRC")" || previous=unset
+	elif [[ $current == false ]]; then
+		return 0
+	else
+		previous="${current:-unset}"
+	fi
+
+	if [[ $current != false ]]; then
+		mca_kde_write "$MCA_KWINRC" false || return 1
+		MCA_CHANGES=$(( MCA_CHANGES + 1 ))
+		changed=1
+	fi
+
+	mca_ledger_add kwin "$MCA_KWINRC" "$previous"
+
+	(( changed )) && mca_note "$(mca_msg "Middle click stops pasting at the next login.")"
+	return 0
+}
+
+# mca_kde_paste_revert <file> <previous value>
+mca_kde_paste_revert() {
+	local file="$1" previous="$2"
+
+	_mca_kde_tool > /dev/null || return 1
+	[[ -f $file ]] || return 1
+
+	# Only what is still recognisably ours. A key somebody has since put a
+	# value of their own into is theirs now.
+	[[ "$(mca_kde_read "$file")" == false ]] || return 1
+
+	[[ $previous == unset ]] && previous=''
+	mca_kde_write "$file" "$previous" || return 1
+
+	# Nothing was in the file but the key, which means there was no file before
+	# this program wrote one. An empty kwinrc says nothing that its absence
+	# does not say better.
+	[[ -s $file ]] || rm -f -- "$file"
+	return 0
+}

src/lib/menu.sh

@@ -194,6 +194,18 @@ mca_ui_status() {
 		fi
 	fi
 
+	# Not an ON/OFF like the rows around it: what is being reported is the state
+	# of the paste, not of a switch, and off is the state this program is after.
+	if mca_kde_available; then
+		if [[ "$(mca_kde_read)" == false ]]; then
+			_mca_row "$(mca_msg "Middle-click paste")" \
+				"${MCA_C_GREEN}$(mca_msg "off")${MCA_C_RESET}"
+		else
+			_mca_row "$(mca_msg "Middle-click paste")" \
+				"${MCA_C_DIM}$(mca_msg "on")${MCA_C_RESET}"
+		fi
+	fi
+
 	_mca_row "$(mca_msg "Last applied")" "$(mca_time_ago "$last")"
 
 	if [[ $CFG_ENABLED == yes ]]; then
@@ -212,9 +224,11 @@ MCA_SETTINGS=(
 	"PatchApps|bool|yes|Electron and CEF applications"
 	"PatchBrowsers|bool|yes|Chromium-based browsers"
 	"PatchFlatpak|bool|yes|Flatpak applications"
+	"PatchSnap|bool|yes|Snap applications"
 	"PatchAutostart|bool|yes|Programs that start themselves at login"
 	"PatchSteam|bool|yes|Steam"
 	"PatchSpotify|bool|yes|Spotify"
+	"DisablePaste|bool|yes|Turn off KDE's middle-click paste"
 	"WatchNewApps|bool|yes|Apply to newly installed applications"
 	"ExtraFlags|text||Additional Chromium arguments"
 )
@@ -495,7 +509,7 @@ mca_ui_menu() {
 		mca_ui_status
 		printf '\n'
 		printf '  [1] %s\n' "$(mca_msg "Turn autoscroll on or off")"
-		printf '  [2] %s\n' "$(mca_msg "Apply now")"
+		printf '  [2] %s\n' "$(mca_msg "Re-apply everything")"
 		printf '  [3] %s\n' "$(mca_msg "Applications")"
 		printf '  [4] %s\n' "$(mca_msg "Settings")"
 		printf '  [q] %s\n' "$(mca_msg "Quit")"
@@ -519,18 +533,24 @@ mca_ui_menu() {
 				fi
 				[[ -n $MCA_UI_NEEDS_ACK ]] && mca_pause
 				;;
+			# Not a plain apply: with the watcher running there is never
+			# anything left for one to do, and a menu entry that answers
+			# "already done" every time is not an action. This is the repair -
+			# everything is taken back and written again from scratch, which is
+			# what fixes an application that drifted, a flag file somebody
+			# edited, or Steam after it restored its own script.
 			2)
-				mca_ui_cooked mca_do_apply
+				mca_ui_cooked mca_do_apply --rebuild
 				mca_pause
 				;;
 			3)
 				if mca_ui_apps; then
-					[[ $CFG_ENABLED == yes ]] && mca_ui_cooked mca_do_apply --changed
+					[[ $CFG_ENABLED == yes ]] && mca_ui_cooked mca_do_apply --rebuild
 				fi
 				;;
 			4)
 				if mca_ui_settings; then
-					[[ $CFG_ENABLED == yes ]] && mca_ui_cooked mca_do_apply --changed
+					[[ $CFG_ENABLED == yes ]] && mca_ui_cooked mca_do_apply --rebuild
 				fi
 				;;
 			q|Q) mca_ui_term_restore; trap - EXIT INT TERM; return 0 ;;

src/lib/patch.sh

@@ -4,21 +4,65 @@
 #
 # There are two ways in, and the order matters:
 #
-#   1. A flag file. Arch's Electron and Chromium wrappers read extra arguments
+#   1. A flag file. Where the distribution wraps Electron and Chromium in a
-#      from $XDG_CONFIG_HOME/<name>-flags.conf. This is the good one - it is the
+#      launcher script that reads extra arguments from
-#      supported way to pass arguments, it survives package upgrades untouched,
+#      $XDG_CONFIG_HOME/<name>-flags.conf - Arch and its derivatives do, and it
-#      and it applies however the program is started, including from a terminal.
+#      is the convention their packages follow - this is the good one: it is
+#      the supported way to pass arguments, it survives package upgrades
+#      untouched, and it applies however the program is started, including from
+#      a terminal.
+#
+#      Nothing is assumed about which distribution this is. The launcher itself
+#      is read, and the route is taken only for a launcher that really does
+#      name such a file. Elsewhere - Debian, Ubuntu, Fedora, openSUSE, where
+#      the equivalent file lives under /etc and is the system's to write -
+#      there is no flag file to use and route 2 answers for everything.
 #
 #   2. A desktop entry. For applications that ship their own binary with no
-#      wrapper - most vendor packages, every Flatpak - there is nowhere else to
+#      wrapper, and for everything a Flatpak or a snap contains, there is
-#      put an argument, so a copy of the entry with the flag appended goes into
+#      nowhere else to put an argument, so a copy of the entry with the flag
-#      ~/.local/share/applications, where it shadows the system one.
+#      appended goes into ~/.local/share/applications, where it shadows the
+#      system one.
 #
 # Nothing outside $HOME is ever written to.
 
 MCA_MARK_BEGIN='# >>> middleclick-autoscroll'
 MCA_MARK_END='# <<< middleclick-autoscroll'
 
+# ---------------------------------------------------------------------------
+# Feature lists
+# ---------------------------------------------------------------------------
+# Both --enable-features and --enable-blink-features take a comma separated
+# list, and Chromium keeps the last one it is given and drops the rest. A
+# second one of the same kind would therefore silently switch off whatever the
+# first one turned on, so an option that is already there is extended instead.
+
+# _mca_list_merge <list> <wanted>
+# The two lists as one, in the order they came and without repeating anything.
+_mca_list_merge() {
+	local out="$1" item
+	for item in ${2//,/ }; do
+		[[ ",$out," == *",$item,"* ]] && continue
+		out="${out:+$out,}$item"
+	done
+	printf '%s' "$out"
+}
+
+# _mca_list_strip <list> <unwanted>
+# The list without any of the named entries.
+_mca_list_strip() {
+	local out='' item
+	for item in ${1//,/ }; do
+		[[ ",$2," == *",$item,"* ]] && continue
+		out="${out:+$out,}$item"
+	done
+	printf '%s' "$out"
+}
+
+# The two options, as a regular expression branch, for the places that have to
+# recognise either of them.
+MCA_FEATURE_OPTS='--enable-blink-features|--enable-features'
+
 # ---------------------------------------------------------------------------
 # Command lines
 # ---------------------------------------------------------------------------
@@ -60,28 +104,32 @@ _mca_exec_after_program() {
 # Prints nothing and returns 1 when there was nothing to change, so callers can
 # tell a real edit from a no-op without diffing.
 #
-# An --enable-blink-features that is already there is extended rather than
+# A feature list that is already on the line is extended rather than repeated.
-# repeated: Chromium keeps the last occurrence of the option and drops the
+# See _mca_list_merge.
-# rest, so a second one would silently disable whatever the first turned on.
 mca_exec_inject() {
 	local line="$1" flagstr="${2:-}" where="${3:-before-fields}"
-	local flag value existing at changed=0
+	local flag opt value existing merged re at changed=0
 	local -a flags
 
 	[[ -n $flagstr ]] || flagstr="$(mca_flags)"
 	read -r -a flags <<< "$flagstr"
 
 	for flag in "${flags[@]}"; do
-		if [[ $flag == --enable-blink-features=* ]]; then
+		case "$flag" in
-			value="${flag#--enable-blink-features=}"
+			--enable-blink-features=*|--enable-features=*)
-			if [[ $line =~ --enable-blink-features=([A-Za-z0-9,_-]*) ]]; then
+				opt="${flag%%=*}"
-				existing="${BASH_REMATCH[1]}"
+				value="${flag#*=}"
-				[[ ",$existing," == *",$value,"* ]] && continue
+				re="(^|[[:space:]])$opt=([^[:space:]]*)"
-				line="${line/--enable-blink-features=$existing/--enable-blink-features=${existing:+$existing,}$value}"
+				if [[ $line =~ $re ]]; then
+					existing="${BASH_REMATCH[2]}"
+					merged="$(_mca_list_merge "$existing" "$value")"
+					[[ $merged == "$existing" ]] && continue
+					line="${line/$opt=$existing/$opt=$merged}"
 					changed=1
 					continue
 				fi
-		fi
+				;;
+		esac
 
 		[[ " $line " == *" $flag "* ]] && continue
 
@@ -107,12 +155,12 @@ mca_exec_inject() {
 # Flag files
 # ---------------------------------------------------------------------------
 
-# mca_flags_apply <program>
+# mca_flags_apply <program> [kind]
 # Writes the flags into the file the program's launcher reads. Returns 0 when
 # the program has such a file (whether or not anything needed changing), 1 when
 # it has none and the desktop entry route has to be used instead.
 mca_flags_apply() {
-	local prog="$1" name target='' existing_target=''
+	local prog="$1" kind="${2:-app}" name target='' existing_target=''
 	local -a candidates=()
 
 	mapfile -t candidates < <(mca_flags_candidates "$prog" | awk '!seen[$0]++')
@@ -123,7 +171,7 @@ mca_flags_apply() {
 	for name in "${candidates[@]}"; do
 		if [[ -f "$MCA_XDG_CONFIG/$name" ]]; then
 			existing_target="$name"
-			_mca_flags_write "$MCA_XDG_CONFIG/$name"
+			_mca_flags_write "$MCA_XDG_CONFIG/$name" "$kind"
 		fi
 	done
 	[[ -n $existing_target ]] && return 0
@@ -133,19 +181,21 @@ mca_flags_apply() {
 	# creating that one also covers every other application using the same
 	# shared Electron.
 	target="${candidates[-1]}"
-	_mca_flags_write "$MCA_XDG_CONFIG/$target"
+	_mca_flags_write "$MCA_XDG_CONFIG/$target" "$kind"
 	return 0
 }
 
-# _mca_flags_write <file>
+# _mca_flags_write <file> [kind]
-# Adds the flags as a marked block, or merges into an --enable-blink-features
+# Adds the flags as a marked block, or merges into a feature list that is
-# line that is already in the file.
+# already in the file.
 _mca_flags_write() {
-	local file="$1" content='' line flag value existing merged=0 block=''
+	local file="$1" kind="${2:-app}"
+	local content='' line flag opt want existing merged=0 block=''
 	local -a flags
+	local -A merged_opts=()
 	local created=0
 
-	read -r -a flags <<< "$(mca_flags)"
+	read -r -a flags <<< "$(mca_flags "$kind")"
 
 	[[ -f $file ]] || created=1
 	if (( ! created )); then
@@ -156,24 +206,31 @@ _mca_flags_write() {
 		fi
 	fi
 
-	# Merge into a blink-features line the user (or a distribution) put there.
+	# Merge into a feature list the user (or a distribution) put there, rather
-	if [[ $content == *--enable-blink-features=* ]]; then
+	# than write a second line of the same option further down.
+	if [[ $content == *--enable-* ]]; then
 		local out=''
 		while IFS= read -r line; do
-			if [[ $line =~ ^[[:space:]]*--enable-blink-features=([A-Za-z0-9,_-]*)[[:space:]]*$ ]]; then
+			if [[ $line =~ ^[[:space:]]*($MCA_FEATURE_OPTS)=([^[:space:]]*)[[:space:]]*$ ]]; then
-				existing="${BASH_REMATCH[1]}"
+				opt="${BASH_REMATCH[1]}"
-				if [[ ",$existing," != *",$MCA_FEATURE,"* ]]; then
+				existing="${BASH_REMATCH[2]}"
-					line="--enable-blink-features=${existing:+$existing,}$MCA_FEATURE"
+				want=''
-				fi
+				for flag in "${flags[@]}"; do
+					[[ $flag == "$opt="* ]] && want="${flag#*=}"
+				done
+				if [[ -n $want ]]; then
+					line="$opt=$(_mca_list_merge "$existing" "$want")"
+					merged_opts["$opt"]=1
 					merged=1
 				fi
+			fi
 			out+="$line"$'\n'
 		done <<< "$content"
 		content="${out%$'\n'}"
 	fi
 
 	for flag in "${flags[@]}"; do
-		(( merged )) && [[ $flag == --enable-blink-features=* ]] && continue
+		[[ -n ${merged_opts["${flag%%=*}"]:-} ]] && continue
 		block+="$flag"$'\n'
 	done
 
@@ -208,7 +265,7 @@ _mca_flags_drop_block() {
 
 # mca_flags_revert <file> <detail>
 mca_flags_revert() {
-	local file="$1" detail="$2" content line out='' existing new
+	local file="$1" detail="$2" content line out='' opt existing new
 
 	[[ -f $file ]] || return 0
 
@@ -228,12 +285,13 @@ mca_flags_revert() {
 
 	if [[ $detail == merged* ]]; then
 		while IFS= read -r line; do
-			if [[ $line =~ ^[[:space:]]*--enable-blink-features=([A-Za-z0-9,_-]*)[[:space:]]*$ ]]; then
+			if [[ $line =~ ^[[:space:]]*($MCA_FEATURE_OPTS)=([^[:space:]]*)[[:space:]]*$ ]]; then
-				existing="${BASH_REMATCH[1]}"
+				opt="${BASH_REMATCH[1]}"
-				new="${existing//$MCA_FEATURE/}"
+				existing="${BASH_REMATCH[2]}"
-				new="${new//,,/,}"; new="${new#,}"; new="${new%,}"
+				# Either name, whichever version of this program put it there.
+				new="$(_mca_list_strip "$existing" "$MCA_BROWSER_FEATURES")"
 				[[ -z $new ]] && continue
-				line="--enable-blink-features=$new"
+				line="$opt=$new"
 			fi
 			out+="$line"$'\n'
 		done <<< "$content"
@@ -339,38 +397,120 @@ mca_desktop_apply() {
 }
 
 # ---------------------------------------------------------------------------
-# Autostart entries
+# Entries outside the search path
 # ---------------------------------------------------------------------------
-# Applications that start themselves at login write their own entry into
+# Two directories hold desktop entries that no part of the XDG search path
-# ~/.config/autostart, pointing straight at their binary. Those bypass the
+# looks at, so nothing the scan does can reach them:
-# desktop entry in the menu completely, which is why Discord launched at login
+#
-# used to behave differently from Discord launched from the menu.
+#   ~/.config/autostart, where applications that start themselves at login
+#   write their own entry, pointing straight at their binary. Those bypass the
+#   entry in the menu completely, which is why Discord launched at login used
+#   to behave differently from Discord launched from the menu.
+#
+#   The desktop folder, where a shortcut somebody dragged out of the menu -
+#   or asked Steam for - lives and nowhere else.
+#
+# Neither can be shadowed from anywhere, so both are edited where they stand,
+# with the original kept.
+
+# _mca_entry_patch_inplace <file> <gate: autostart|apps>
+# One desktop entry that lives outside the XDG search path, edited where it is
+# because there is nowhere to shadow it from.
+#
+# What decides whether an application here is in scope differs by where the
+# entry came from, which is what the gate says: an autostart entry follows the
+# autostart setting, a shortcut follows the same rules as the application it is
+# a shortcut to.
+_mca_entry_patch_inplace() {
+	local file="$1" gate="$2"
+	local id prog packaging=native content backup kind copy
+
+	# Already ours, and normally that is the end of it: what is in there is what
+	# this version put there. Not so for a file the ledger has no record of -
+	# nothing would ever look at that one again, neither the undo a change of
+	# flags goes through nor this, which leaves a marked file alone, and it would
+	# keep an answer from an older version for good. The copy taken before the
+	# edit is named after the path and is still there, so the file goes back to
+	# what it was and is written again below.
+	if grep -q "^$MCA_MARK_INPLACE=" "$file" 2>/dev/null; then
+		mca_ledger_has "$file" && return 0
+		copy="$MCA_BACKUPDIR/$(mca_backup_name "$file")"
+		[[ -f $copy ]] || return 0
+		cp -p -- "$copy" "$file" 2>/dev/null || return 0
+	fi
+
+	_mca_desktop_read "$file"
+	[[ -n $DE_EXEC ]] || return 0
+	[[ $DE_HIDDEN == true ]] && return 0
+
+	mca_exec_program "$DE_EXEC" || return 0
+	prog="$MCA_PROG"
+
+	# A Flatpak or a snap entry names the wrapper rather than the application.
+	# The scan resolves those into an id; outside the scan the same has to
+	# happen here, or every Flatpak looks like the flatpak program itself.
+	if [[ ${prog##*/} == flatpak ]]; then
+		mca_exec_flatpak_id "$DE_EXEC" || return 0
+		prog="flatpak:$MCA_PROG"
+		packaging=flatpak
+	elif mca_snap_name "$prog"; then
+		prog="snap:$MCA_PROG"
+		packaging=snap
+	fi
+
+	# An entry that starts Steam is left where it is. Steam takes nothing
+	# from a command line that would help, and what it does take belongs to
+	# the web helper script in its own installation.
+	mca_prog_is_steam "$prog" && return 0
+
+	case "$packaging" in
+		flatpak) mca_flatpak_is_chromium "${prog#flatpak:}" || return 0 ;;
+		snap)    mca_snap_is_chromium "${prog#snap:}" || return 0 ;;
+		*)       mca_is_chromium "$prog" || return 0 ;;
+	esac
+
+	mca_desktop_is_browser && kind=browser || kind=app
+
+	if [[ $gate == autostart ]]; then
+		[[ $CFG_AUTOSTART == yes ]] || return 0
+	else
+		id="${file##*/}"; id="${id%.desktop}"
+		mca_kind_wanted "$kind" "$id" "$packaging" || return 0
+	fi
+
+	content="$(_mca_desktop_transform "$file" "$MCA_MARK_INPLACE" \
+		"$(mca_flags "$kind")")"
+
+	[[ -n $content ]] || return 0
+	[[ "$content" == "$(< "$file")" ]] && return 0
+
+	backup="$(mca_backup "$file")" || return 0
+	if mca_write_if_changed "$file" "$content"$'\n'; then
+		MCA_CHANGES=$(( MCA_CHANGES + 1 ))
+	fi
+	mca_ledger_add inplace "$file" "$backup"
+}
 
 mca_autostart_apply() {
-	local dir="$MCA_XDG_CONFIG/autostart" file exec_line prog content backup
+	local dir="$MCA_XDG_CONFIG/autostart" file
 
 	[[ -d $dir ]] || return 0
 
 	for file in "$dir"/*.desktop; do
 		[[ -f $file ]] || continue
-		grep -q "^$MCA_MARK_INPLACE=" "$file" 2>/dev/null && continue
+		_mca_entry_patch_inplace "$file" autostart
+	done
+}
 
-		exec_line="$(mca_desktop_get "$file" Exec)"
+mca_shortcuts_apply() {
-		[[ -n $exec_line ]] || continue
+	local dir file
+	dir="$(mca_desktop_folder)"
 
-		mca_exec_program "$exec_line" || continue
+	[[ -d $dir ]] || return 0
-		prog="$MCA_PROG"
-		mca_is_chromium "$prog" || continue
 
-		content="$(_mca_desktop_transform "$file" "$MCA_MARK_INPLACE")"
+	for file in "$dir"/*.desktop; do
-		[[ -n $content ]] || continue
+		[[ -f $file ]] || continue
-		[[ "$content" == "$(< "$file")" ]] && continue
+		_mca_entry_patch_inplace "$file" apps
-
-		backup="$(mca_backup "$file")" || continue
-		if mca_write_if_changed "$file" "$content"$'\n'; then
-			MCA_CHANGES=$(( MCA_CHANGES + 1 ))
-		fi
-		mca_ledger_add inplace "$file" "$backup"
 	done
 }
 
@@ -418,6 +558,53 @@ mca_spotify_apply() {
 	return 0
 }
 
+# ---------------------------------------------------------------------------
+# Leftovers
+# ---------------------------------------------------------------------------
+
+# mca_prune_orphans
+# Forgets changes there is no longer anything to undo.
+#
+# Uninstalling something deletes its entry from /usr/share/applications, but the
+# copy shadowing it is in the user's home and pacman knows nothing about it. It
+# would sit in the menu forever, offering to start a program that is no longer
+# installed - and the watcher would not notice, because a plain apply only ever
+# looks at what is there now. A file that was edited where it stood and has
+# since been deleted is the same problem from the other side: its record would
+# have `disable` put the file back.
+mca_prune_orphans() {
+	local kind path source line
+	local -a lines=()
+
+	[[ -f $MCA_LEDGER ]] || return 0
+	mapfile -t lines < "$MCA_LEDGER"
+
+	for line in "${lines[@]}"; do
+		IFS=$'\t' read -r kind path source <<< "$line"
+
+		# An entry that was edited where it stood and has since been deleted -
+		# a game shortcut dragged to the wastebasket, an autostart entry the
+		# application removed. There is nothing left to put back, and keeping
+		# the record would have `disable` recreate a file the user threw away.
+		if [[ $kind == inplace && ! -e $path ]]; then
+			[[ -n $source ]] && rm -f -- "$MCA_BACKUPDIR/$source"
+			mca_ledger_forget "$path"
+			continue
+		fi
+
+		[[ $kind == shadow && -n $source ]] || continue
+		[[ -e $source ]] && continue
+
+		# Only ever remove something still recognisably ours.
+		if [[ -f $path ]] && grep -q "^$MCA_MARK_SHADOW=" "$path" 2>/dev/null; then
+			rm -f -- "$path"
+			MCA_CHANGES=$(( MCA_CHANGES + 1 ))
+		fi
+		mca_ledger_forget "$path"
+	done
+	return 0
+}
+
 # ---------------------------------------------------------------------------
 # Undo
 # ---------------------------------------------------------------------------
@@ -459,6 +646,10 @@ mca_revert_all() {
 				mca_steam_revert "$path" "$detail" \
 					&& MCA_CHANGES=$(( MCA_CHANGES + 1 ))
 				;;
+			kwin)
+				mca_kde_paste_revert "$path" "$detail" \
+					&& MCA_CHANGES=$(( MCA_CHANGES + 1 ))
+				;;
 		esac
 	done < <(tac "$MCA_LEDGER" 2>/dev/null)
 

src/lib/steam.sh

@@ -9,19 +9,35 @@
 #
 #   ~/.local/share/Steam/ubuntu12_64/steamwebhelper_sniper_wrap.sh
 #
-# Steam checksums that script at every start and restores it when it differs,
+# Steam compares the installed files against its manifest at every start - by
-# which is why the launcher gets -noverifyfiles as well. The trade-off is real
+# size and timestamp rather than by content - and restores whatever differs.
-# and belongs to the user, so this is a switch of its own rather than part of
+# So the patch is written to look untouched: the bytes the flag costs are taken
-# the general application handling: with verification off, Steam no longer
+# back out of the script's comments and the timestamp is put back afterwards,
-# repairs a damaged installation by itself.
+# which leaves a file that is byte-for-byte the size Steam recorded and as old
+# as Steam left it. A client that verifies its files finds nothing to repair
+# and the flag survives however Steam was started - from the menu, from a game
+# shortcut, from a launcher like Heroic, from a terminal.
+#
+# A patch that changes the length is not an option, and no switch covers for
+# one. Steam checks its files at a start it was given arguments for, but also
+# at the shutdown it runs itself - and that one has no -noverifyfiles on its
+# command line, whatever the session was started with. What a single wrong
+# length costs is the whole client package downloaded, extracted and installed
+# again, and a client that quits at the end of it instead of coming up. So the
+# flag either fits in the space the comments give back, or it is not written at
+# all: no autoscroll in the interface is a smaller thing than a client that
+# reinstalls itself.
 #
 # The file comes back on every client update, and the watcher re-applies the
 # patch when that happens.
 
-MCA_STEAM_LAUNCH_FLAG='-noverifyfiles'
-
 # Every place a Steam installation is known to live, resolved and de-duplicated
 # because ~/.steam/steam is normally a symlink into ~/.local/share.
+#
+# Which of these is the real one depends on how Steam was installed: Valve's
+# own package and the Arch one use ~/.local/share/Steam, Debian's puts it in
+# ~/.steam/debian-installation, and the Flatpak and the snap each keep it
+# inside the private tree their sandbox gives them.
 mca_steam_roots() {
 	local candidates=(
 		"$MCA_XDG_DATA/Steam"
@@ -29,6 +45,8 @@ mca_steam_roots() {
 		"$HOME/.steam/root"
 		"$HOME/.steam/debian-installation"
 		"$HOME/.var/app/com.valvesoftware.Steam/.local/share/Steam"
+		"$HOME/.var/app/com.valvesoftware.Steam/data/Steam"
+		"$HOME/snap/steam/common/.local/share/Steam"
 	)
 	local dir real
 	local -A seen=()
@@ -92,12 +110,116 @@ _mca_steam_exec_line() {
 	' "$1" 2>/dev/null
 }
 
+# _mca_steam_build <script> <flags>
+# The patched script on stdout: the flags appended to the line that starts the
+# web helper, and the same number of bytes taken back out of the script's
+# comments, so that the file Steam finds is the length Steam wrote down.
+# Everything else - setting up the container runtime, deciding whether the
+# sandbox can be used - is left alone.
+#
+# Comments are eaten from the bottom up, so the header that says what the
+# script is for is the last thing to lose anything, and the '#' itself always
+# stays: a line that loses it stops being a comment and starts being a command.
+# Fails when the comments are too short to pay for the flags.
+_mca_steam_build() {
+	local script="$1" flags="$2" lineno need
+
+	lineno="$(_mca_steam_exec_line "$script")"
+	[[ -n $lineno ]] || return 1
+
+	need="$(printf '%s' " $flags" | wc -c)"
+	need="${need//[^0-9]/}"
+
+	# LC_ALL=C so awk counts bytes: a comment with an accent in it is shorter
+	# in characters than it is on disk, and it is the disk that Steam measures.
+	LC_ALL=C awk -v n="$lineno" -v f=" $flags" -v need="$need" '
+		{ lines[NR] = (NR == n ? $0 f : $0) }
+		END {
+			for (i = NR; i >= 2 && need > 0; i--) {
+				if (i == n) continue
+				p = index(lines[i], "#")
+				if (p == 0) continue
+				# Only a line that is nothing but a comment; a trailing one
+				# sits behind a command that has to stay intact.
+				if (substr(lines[i], 1, p - 1) ~ /[^ \t]/) continue
+				can = length(lines[i]) - p
+				if (can <= 0) continue
+				if (can > need) can = need
+				lines[i] = substr(lines[i], 1, length(lines[i]) - can)
+				need -= can
+			}
+			if (need > 0) exit 1
+			for (i = 1; i <= NR; i++) print lines[i]
+		}
+	' "$script"
+}
+
+# _mca_steam_same_size <script> <content>
+# Whether writing that content leaves the file at the size it has now. Measured
+# rather than worked out: a script without a final newline gains one on the way
+# through awk, and one byte is all it takes for Steam to notice.
+_mca_steam_same_size() {
+	local script="$1" content="$2"
+	(( $(wc -c < "$script") == $(printf '%s\n' "$content" | wc -c) ))
+}
+
+# _mca_steam_refresh_backup <script>
+# A client update brings a new version of the script, and the copy kept from
+# before it is no longer what putting it back means. Only ever done while the
+# script is unpatched, so the copy that replaces it is Steam's own.
+_mca_steam_refresh_backup() {
+	local script="$1" name
+	name="$(mca_backup_name "$script")"
+
+	[[ -e "$MCA_BACKUPDIR/$name" ]] || return 0
+	cmp -s -- "$script" "$MCA_BACKUPDIR/$name" && return 0
+	cp -p -- "$script" "$MCA_BACKUPDIR/$name" 2>/dev/null || true
+}
+
+# _mca_steam_settle <script> <flags>
+# The script is already patched. Whether that is a patch Steam can live with is
+# a question of length: an earlier version of this program appended the flag
+# where the comments could not pay for it, which leaves the script longer than
+# the file Steam wrote down - and a client that checks its files reinstalls
+# itself over that, then quits instead of starting.
+#
+# Rebuilt from the untouched original kept when the script was first patched,
+# never from the patched file, the flag either fits this time or the original
+# goes back and Steam is left with a client it recognises.
+_mca_steam_settle() {
+	local script="$1" flags="$2" name copy out
+
+	name="$(mca_backup_name "$script")"
+	copy="$MCA_BACKUPDIR/$name"
+
+	# Nothing to compare against, so nothing can be said about the length.
+	[[ -f $copy ]] || return 0
+
+	# Already the length Steam expects: the patch is a good one.
+	(( $(wc -c < "$script") == $(wc -c < "$copy") )) && return 0
+
+	if out="$(_mca_steam_build "$copy" "$flags")" && _mca_steam_same_size "$copy" "$out"; then
+		if mca_write_if_changed "$script" "$out"$'\n'; then
+			MCA_CHANGES=$(( MCA_CHANGES + 1 ))
+		fi
+		chmod +x -- "$script" 2>/dev/null || true
+		touch -r "$copy" -- "$script" 2>/dev/null || true
+		mca_ledger_add steam "$script" "$name"
+		return 0
+	fi
+
+	mca_steam_revert "$script" "$name"
+	mca_ledger_forget "$script"
+	mca_note "$(mca_msg "Steam's interface cannot be given the flag without leaving a file Steam would reinstall; the change has been taken back.")"
+	return 0
+}
+
 # mca_steam_apply
-# Appends the flags to the line that starts the web helper. Everything else in
+# Puts the flags into every Steam installation that has the script, and only
-# the script - setting up the container runtime, deciding whether the sandbox
+# where that can be done without changing how long the file is. Returns 1 when
-# can be used - is left alone.
+# there is no Steam to patch at all.
 mca_steam_apply() {
-	local root script backup flags lineno found=0 out
+	local root script backup flags found=0 out
 
 	flags="$(mca_flags)"
 
@@ -105,24 +227,37 @@ mca_steam_apply() {
 		script="$(mca_steam_script "$root")" || continue
 		found=1
 
-		mca_steam_script_patched "$script" && continue
+		if mca_steam_script_patched "$script"; then
-
+			_mca_steam_settle "$script" "$flags"
-		lineno="$(_mca_steam_exec_line "$script")"
-		if [[ -z $lineno ]]; then
-			# A client update changed how the helper is started. Leaving the
-			# file alone is the only safe answer: this script is what starts
-			# Steam's entire interface.
-			mca_note "$(mca_msg "Steam starts its interface in a way this version does not recognise; leaving it alone.")"
 			continue
 		fi
 
-		out="$(awk -v n="$lineno" -v f=" $flags" 'NR == n { $0 = $0 f } { print }' "$script")" || continue
+		_mca_steam_refresh_backup "$script"
+
+		# Either the comments can pay for the flag or nothing is written.
+		# A longer file is one Steam reinstalls itself over; a client update
+		# that changed how the helper is started leaves no line to patch at
+		# all. Both end here, and this script is what starts Steam's entire
+		# interface, so leaving it alone is the only safe answer to either.
+		if ! { out="$(_mca_steam_build "$script" "$flags")" \
+			&& _mca_steam_same_size "$script" "$out"; }
+		then
+			mca_note "$(mca_msg "Steam starts its interface in a way this version cannot change without Steam noticing; leaving it alone.")"
+			continue
+		fi
 
 		backup="$(mca_backup "$script")" || continue
 		if mca_write_if_changed "$script" "$out"$'\n'; then
 			MCA_CHANGES=$(( MCA_CHANGES + 1 ))
 		fi
 		chmod +x -- "$script" 2>/dev/null || true
+
+		# Steam looks at when the file was last written as well as at how big
+		# it is, and the copy taken before the edit still carries the original
+		# timestamp. Putting it back costs nothing and removes the other half
+		# of what the client would notice.
+		touch -r "$MCA_BACKUPDIR/$backup" -- "$script" 2>/dev/null || true
+
 		mca_ledger_add steam "$script" "$backup"
 	done < <(mca_steam_roots)
 
@@ -150,12 +285,3 @@ mca_steam_revert() {
 	chmod +x -- "$script" 2>/dev/null || true
 	return 0
 }
-
-# mca_steam_desktop_apply <id> <source entry>
-# Steam restores its own files at every start unless it is told not to verify
-# them, so the launcher entry carries that switch. It goes directly after the
-# program because Steam reads its options before the steam:// argument that the
-# right-click actions pass.
-mca_steam_desktop_apply() {
-	mca_desktop_apply "$1" "$2" "$MCA_STEAM_LAUNCH_FLAG" after-program
-}

src/middleclick-autoscroll

@@ -17,7 +17,7 @@ set -uo pipefail
 
 MCA_LIBDIR="${MCA_LIBDIR:-@LIBDIR@}"
 
-for _mod in common config detect patch steam apply menu; do
+for _mod in common config detect patch steam kde apply menu; do
 	# shellcheck source=/dev/null
 	if ! source "$MCA_LIBDIR/$_mod.sh"; then
 		printf 'middleclick-autoscroll: cannot load %s/%s.sh\n' "$MCA_LIBDIR" "$_mod" >&2
@@ -56,10 +56,6 @@ mca_do_enable() {
 
 	mca_ok "$(mca_msg "Autoscroll is on for %d applications." "$MCA_N_ON")"
 
-	if [[ $CFG_STEAM == yes ]] && mca_steam_installed; then
-		mca_note "$(mca_msg "Steam's launcher now skips its file check, which is what keeps the change from being undone at every start.")"
-	fi
-
 	mca_note "$(mca_msg "Applications that are already running pick this up when they are restarted.")"
 }
 
@@ -76,11 +72,11 @@ mca_do_disable() {
 }
 
 mca_do_apply() {
-	local changed=0 arg
+	local rebuild=0 arg
 
 	for arg in "$@"; do
 		case "$arg" in
-			--changed) changed=1 ;;
+			--rebuild) rebuild=1 ;;
 			--quiet)   MCA_QUIET=1 ;;
 		esac
 	done
@@ -95,25 +91,36 @@ mca_do_apply() {
 		return 1
 	fi
 
-	# A settings change can take an application out of scope as well as bring
+	# Start from a clean slate. Needed after a settings change, which can take
-	# one in, and only a full undo can tell the difference, so that path starts
+	# an application out of scope as well as bring one in and where only a full
-	# from a clean slate. The watcher never does this: rewriting files that are
+	# undo can tell the difference, and it is what makes the repair a repair:
-	# already correct would make it trigger itself.
+	# whatever drifted is written again rather than left because it is "already
-	if (( changed )); then
+	# applied".
+	#
+	# The watcher never does this. Rewriting files that are already correct
+	# would change their timestamps, and it is watching those directories.
+	if (( rebuild )); then
 		mca_revert
 	fi
 
 	mca_apply
 
-	if (( MCA_CHANGES )); then
+	if (( rebuild )); then
+		mca_ok "$(mca_msg "Applied again to %d applications." "$MCA_N_ON")"
+		mca_say "  $(mca_msg "Applications that are already running pick this up when they are restarted.")"
+	elif (( MCA_CHANGES )); then
 		mca_ok "$(mca_msg "Applied to %d applications." "$MCA_N_ON")"
 		mca_say "  $(mca_msg "Applications that are already running pick this up when they are restarted.")"
 	else
 		mca_ok "$(mca_msg "Already applied to %d applications." "$MCA_N_ON")"
 	fi
 
-	if [[ $CFG_WATCH == yes ]] && mca_watch_available && ! mca_watch_enabled; then
+	if [[ $CFG_WATCH == yes ]] && mca_watch_available; then
+		if mca_watch_enabled; then
+			mca_watch_refresh
+		else
 			mca_watch_enable || true
+		fi
 	elif [[ $CFG_WATCH != yes ]] && mca_watch_enabled; then
 		mca_watch_disable
 	fi
@@ -160,6 +167,7 @@ mca_do_help() {
 	  enable              $(mca_msg "Turn autoscroll on")
 	  disable             $(mca_msg "Turn it off and put everything back")
 	  apply               $(mca_msg "Apply to anything installed since the last run")
+	  apply --rebuild     $(mca_msg "Take everything back and apply it again")
 	  status              $(mca_msg "Show what is covered")
 	  list                $(mca_msg "List every application that was found")
 	  -h, --help          $(mca_msg "Show this help")