From 0c22a21a2490024110d8a61afd4d385b2e91de6c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Fri, 7 Oct 2016 17:54:09 +0200
Subject: [PATCH] window-tracker: Consider Flatpak ID for window matching

Our window matching currently fails frequently with Flatpak
applications, as one of the primary hints used to link windows
with .desktop files - the WM_CLASS - no longer matches when
flatpak renames the exported .desktop file. Worse, as Flatpak
applications are run in their own PID namespace, different
apps frequently share a common _NET_WM_PID, resulting in
unrelated apps being grouped together by one of the fallback
paths. To match Flatpak applications reliably, take the newly
exported Flatpak ID into account.

https://bugzilla.gnome.org/show_bug.cgi?id=772615
---
 src/shell-window-tracker.c | 72 +++++++++++++++++++++++++++++++-------
 1 file changed, 60 insertions(+), 12 deletions(-)

diff --git a/src/shell-window-tracker.c b/src/shell-window-tracker.c
index ad1219c13..f87e6a3ae 100644
--- a/src/shell-window-tracker.c
+++ b/src/shell-window-tracker.c
@@ -202,9 +202,39 @@ get_app_from_window_wmclass (MetaWindow  *window)
   return NULL;
 }
 
+/*
+ * get_app_from_id:
+ * @window: a #MetaWindow
+ *
+ * Looks only at the given window, and attempts to determine
+ * an application based on %id.  If one can't be determined,
+ * return %NULL.
+ *
+ * Return value: (transfer full): A newly-referenced #ShellApp, or %NULL
+ */
+static ShellApp *
+get_app_from_id (MetaWindow  *window,
+                 const char  *id)
+{
+  ShellApp *app;
+  ShellAppSystem *appsys;
+  char *desktop_file;
+
+  g_return_val_if_fail (id != NULL, NULL);
+
+  appsys = shell_app_system_get_default ();
+
+  desktop_file = g_strconcat (id, ".desktop", NULL);
+  app = shell_app_system_lookup_app (appsys, desktop_file);
+  if (app)
+    g_object_ref (app);
+
+  g_free (desktop_file);
+  return app;
+}
+
 /*
  * get_app_from_gapplication_id:
- * @monitor: a #ShellWindowTracker
  * @window: a #MetaWindow
  *
  * Looks only at the given window, and attempts to determine
@@ -216,24 +246,35 @@ get_app_from_window_wmclass (MetaWindow  *window)
 static ShellApp *
 get_app_from_gapplication_id (MetaWindow  *window)
 {
-  ShellApp *app;
-  ShellAppSystem *appsys;
   const char *id;
-  char *desktop_file;
-
-  appsys = shell_app_system_get_default ();
 
   id = meta_window_get_gtk_application_id (window);
   if (!id)
     return NULL;
 
-  desktop_file = g_strconcat (id, ".desktop", NULL);
-  app = shell_app_system_lookup_app (appsys, desktop_file);
-  if (app)
-    g_object_ref (app);
+  return get_app_from_id (window, id);
+}
 
-  g_free (desktop_file);
-  return app;
+/*
+ * get_app_from_flatpak_id:
+ * @window: a #MetaWindow
+ *
+ * Looks only at the given window, and attempts to determine
+ * an application based on its Flatpak ID.  If one can't be determined,
+ * return %NULL.
+ *
+ * Return value: (transfer full): A newly-referenced #ShellApp, or %NULL
+ */
+static ShellApp *
+get_app_from_flatpak_id (MetaWindow  *window)
+{
+  const char *id;
+
+  id = meta_window_get_flatpak_id (window);
+  if (!id)
+    return NULL;
+
+  return get_app_from_id (window, id);
 }
 
 /*
@@ -354,6 +395,13 @@ get_app_for_window (ShellWindowTracker    *tracker,
   if (meta_window_is_remote (window))
     return _shell_app_new_for_window (window);
 
+  /* Check if the window was opened from within a Flatpak sandbox; if this
+   * is the case, a corresponding .desktop file is guaranteed to match;
+   */
+  result = get_app_from_flatpak_id (window);
+  if (result != NULL)
+    return result;
+
   /* Check if the window has a GApplication ID attached; this is
    * canonical if it does
    */