fix: build on debian 13, without the own lock screen there

doc/face-unlock.1.scd

@@ -267,7 +267,8 @@ so does the bubble, above the lock screen too.
 	picture there, one at random from a folder, or _none_; *Blur the
 	wallpaper* blurs it. If the agent dies while this screen is locked, the
 	compositor keeps it locked, and the agent takes the lock back when it
-	starts again.
+	starts again. It needs Qt 6.10 or newer: with older Qt (Debian 13) the
+	menu does not offer it, and *lock* asks logind to lock.
 
 	Hyprland only starts the agent's user service under uwsm. Without it,
 	*enable* and *status* show what to add to its config.

src/agent/main.cpp

@@ -13,6 +13,8 @@
 //   --choose-lock-screen
 //                    open the window that asks which lock screen to use
 //                    where it is a program of its own, and print the answer
+//   --has-own-lock   for the menu: exits 0 when this build has face-unlock's
+//                    own lock screen (see SessionLock::built)
 
 #include "agentsocket.h"
 #include "bubblecontroller.h"
@@ -233,6 +235,9 @@ void scheduleDemo(BubbleController *bubble)
 
 int main(int argc, char **argv)
 {
+    if (argc == 2 && std::strcmp(argv[1], "--has-own-lock") == 0) {
+        return SessionLock::built ? 0 : 1;
+    }
     forkForLock(argc, argv);
     QGuiApplication app(argc, argv);
     app.setApplicationName(QStringLiteral("face-unlock-agent"));

src/agent/sessionlock.cpp

@@ -64,12 +64,15 @@ public:
     {
         return m_configured;
     }
+#if QT_VERSION >= QT_VERSION_CHECK(6, 10, 0)
     // Qt commits a new role at once, as xdg-shell wants. A lock surface must
-    // not be committed before it has acknowledged its first size.
+    // not be committed before it has acknowledged its first size. Older Qt
+    // cannot be stopped from that (see SessionLock::built).
     bool commitSurfaceRole() const override
     {
         return false;
     }
+#endif
     void applyConfigure() override
     {
         window()->resizeFromApplyConfigure(m_size);
@@ -83,7 +86,11 @@ protected:
         if (!m_configured) {
             m_configured = true;
             applyConfigure();
+#if QT_VERSION >= QT_VERSION_CHECK(6, 9, 0)
             window()->updateExposure();
+#else
+            window()->sendRecursiveExposeEvent();
+#endif
         } else {
             window()->applyConfigureWhenPossible();
         }
@@ -151,7 +158,7 @@ SessionLock::~SessionLock()
 
 bool SessionLock::available()
 {
-    return Wayland::hasGlobal("ext_session_lock_manager_v1");
+    return built && Wayland::hasGlobal("ext_session_lock_manager_v1");
 }
 
 QString SessionLock::markerPath()

src/agent/sessionlock.h

@@ -20,6 +20,7 @@
 #include <QObject>
 #include <QPointer>
 #include <QUrl>
+#include <QtGlobal>
 
 class BubbleController;
 class LockScreenController;
@@ -37,7 +38,12 @@ public:
     SessionLock(QQmlEngine *engine, BubbleController *bubble, LockScreenController *screen, UserConfig *config, QObject *parent = nullptr);
     ~SessionLock() override;
 
-    // Whether the compositor offers ext-session-lock.
+    // Whether this build has it. Qt before 6.10 commits a window's surface
+    // before a lock surface may be committed, which the protocol forbids.
+    static constexpr bool built = QT_VERSION >= QT_VERSION_CHECK(6, 10, 0);
+
+    // Whether it can lock here: built, and the compositor offers
+    // ext-session-lock.
     static bool available();
 
     // From the lock request until the lock is gone again.

src/face-unlock

@@ -126,11 +126,16 @@ fu_do_enable() {
 			;;
 	esac
 	# Where the lock screen is a program of its own: face-unlock's, with the
-	# bubble, or that program with a line of text. Asked once.
+	# bubble, or that program with a line of text. Asked once. Without
-	if fu_own_lock_here && [[ -n ${WAYLAND_DISPLAY:-} && -z $(fu_config_get LockScreenStyle) ]]; then
+	# face-unlock's own (older Qt) there is nothing to ask.
+	if [[ $FU_DESKTOP != plasma && $FU_DESKTOP != gnome && -z $(fu_config_get LockScreenStyle) ]]; then
+		if ! fu_own_lock_here; then
+			fu_lock_style_set yours
+		elif [[ -n ${WAYLAND_DISPLAY:-} ]]; then
 			fu_say "  $(fu_msg "Pick your lock screen in the window.")"
 			fu_lock_choose || fu_note "$(fu_msg "No lock screen picked. You can do it later under Settings.")"
 		fi
+	fi
 	if fu_pam_lockers_here && fu_pam_lockers_enabled && [[ $(fu_config_get LockScreenStyle) != own ]]; then
 		fu_note "$(fu_msg "The lock screen (%s) takes your face too. If it does not scan when you come back, press Enter on the empty password field." "$(fu_pam_lockers_list)")"
 	fi

src/lib/menu.sh

@@ -562,7 +562,7 @@ fu_ui_settings() {
 	for spec in "${FU_SETTINGS[@]}"; do
 		IFS='|' read -r scope key type default label choice need only <<< "$spec"
 		[[ $only == lockers ]] && ! fu_pam_lockers_here && continue
-		[[ $only == ownlock && ( $FU_DESKTOP == plasma || $FU_DESKTOP == gnome ) ]] && continue
+		[[ $only == ownlock ]] && ! fu_own_lock_here && continue
 		# A heading has its label where the key would be.
 		[[ $scope == group ]] && label="$key" key=''
 		scopes+=("$scope"); keys+=("$key"); types+=("$type"); defaults+=("$default")

src/lib/system.sh

@@ -313,8 +313,18 @@ fu_gnome_extension_disable() {
 FU_HYPRLOCK_SNIPPET="$FU_XDG_CONFIG/$FU_NAME/hyprlock.conf"
 FU_HYPRLOCK_MARK="# $FU_NAME: what face unlock is doing, at the top"
 
+# fu_own_lock_here
+# Whether face-unlock's own lock screen is on offer: where the lock screen is
+# a program of its own, and the agent was built with it (Qt 6.10 and newer).
+FU_OWN_LOCK=''
+
 fu_own_lock_here() {
-	[[ $FU_DESKTOP != plasma && $FU_DESKTOP != gnome ]]
+	[[ $FU_DESKTOP != plasma && $FU_DESKTOP != gnome ]] || return 1
+	if [[ -z $FU_OWN_LOCK ]]; then
+		FU_OWN_LOCK=no
+		"$FU_AGENT" --has-own-lock > /dev/null 2>&1 && FU_OWN_LOCK=yes
+	fi
+	[[ $FU_OWN_LOCK == yes ]]
 }
 
 # fu_hyprlock_text_on