[gnome-shell] shell-app: Never allow opening new windows while an app is starting

[Florian Müllner <fmuellner src gnome org>]

commit 00e95de1148296fbf6f1eece0552cfd07242ac44
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Thu Aug 1 17:22:50 2019 +0200

    shell-app: Never allow opening new windows while an app is starting
    
    We allow opening new windows as a fallback in case the app doesn't give
    us explicit information about it, but we don't want to allow opening new
    windows if we're unable to ask for this information (we can only use the
    APIs to get this information while the app is RUNNING).
    
    So always return FALSE in case the app is STARTING, always return TRUE
    in case the app is STOPPED (starting an app always opens a new window)
    and go through the usual checks in case the app is RUNNING (and
    eventually fall back to FALSE).
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/121

 src/shell-app.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/src/shell-app.c b/src/shell-app.c
index 7968e3358f..33d5ec3a7a 100644
--- a/src/shell-app.c
+++ b/src/shell-app.c
@@ -604,10 +604,12 @@ shell_app_can_open_new_window (ShellApp *app)
   GDesktopAppInfo *desktop_info;
   const char * const *desktop_actions;
 
-  /* Apps that are not running can always open new windows, because
-     activating them would open the first one */
-  if (!app->running_state)
-    return TRUE;
+  /* Apps that are stopped can always open new windows, because
+   * activating them would open the first one; if they are starting,
+   * we cannot tell whether they can open additional windows until
+   * they are running */
+  if (app->state != SHELL_APP_STATE_RUNNING)
+    return app->state == SHELL_APP_STATE_STOPPED;
 
   state = app->running_state;