Merge branch 'master' into 'issue1084'

# Conflicts:
#   gdk/gdk.c

diff --cc gdk/gdk-private.h
index c6a45ed48f4c299eedb2689e3bf1bab486da1835,2d96acc2da71e9807865138874f3a7d2f27f71ce..f6c712c3e77295dfaa2d01c2b444d0f269f9f032
--- 1/gdk/gdk-private.h
--- 2/gdk/gdk-private.h
+++ b/gdk/gdk-private.h
@@@ -39,7 -31,6 +31,8 @@@ void gdk_display_set_double_click_dista
  void gdk_display_set_cursor_theme          (GdkDisplay   *display,
                                              const char   *theme,
                                              int           size);
+ gboolean gdk_running_in_sandbox (void);
  
 +const gchar *   gdk_get_startup_notification_id (void);
 +
  #endif /* __GDK__PRIVATE_H__ */

diff --cc gdk/gdk.c
index 94d27ee87ed33a220186cbf0b73ee6841771b111,b92d374cc95df87200db3848843e1f19ecef341e..b6c3bda972e4612b645bb141a6c470efd5c806a5
--- 1/gdk/gdk.c
--- 2/gdk/gdk.c
+++ b/gdk/gdk.c
@@@ -250,22 -216,19 +250,35 @@@ gdk_display_open_default (void
    return display;
  }
  
 +/*< private >
 + *
 + * gdk_get_startup_notification_id
 + *
 + * Returns the original value of the DESKTOP_STARTUP_ID environment
 + * variable if it was defined and valid, or %NULL otherwise.
 + *
 + * Returns: (nullable) (transfer none): the original value of the
 + *   DESKTOP_STARTUP_ID environment variable, or %NULL.
 + */
 +const gchar *
 +gdk_get_startup_notification_id (void)
 +{
 +  return startup_notification_id;
 +}
 +
+ gboolean
+ gdk_running_in_sandbox (void)
+ {
+   char *path;
+   gboolean ret;
+ 
+   path = g_build_filename (g_get_user_runtime_dir (), "flatpak-info", NULL);
+   ret = g_file_test (path, G_FILE_TEST_EXISTS);
+   g_free (path);
+ 
+   return ret;
+ }
+ 
  /**
   * SECTION:threads
   * @Short_description: Functions for using GDK in multi-threaded programs

diff --cc gdk/gdkdisplay.c
Simple merge

diff --cc gdk/gdkdisplayprivate.h
Simple merge

diff --cc gdk/wayland/gdkdisplay-wayland.c
Simple merge

diff --cc gdk/x11/gdkdisplay-x11.c
Simple merge