main: Temporarily tie meta_quit() to meta_context_terminate*()

Makes it possible for mutter internally to use meta_quit() both if we're
running using a MetaContext or the scattered functions.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1861>

src/core/main.c

@@ -83,7 +83,7 @@
 #include "core/util-private.h"
 #include "meta/compositor.h"
 #include "meta/meta-backend.h"
-#include "meta/meta-enums.h"
+#include "meta/meta-context.h"
 #include "meta/meta-x11-errors.h"
 #include "ui/ui.h"
 #include "x11/session.h"
@@ -888,6 +888,9 @@ meta_run (void)
   return meta_exit_code;
 }
 
+MetaContext *
+meta_get_context_temporary (void);
+
 /**
  * meta_quit:
  * @code: The success or failure code to return to the calling process.
@@ -901,11 +904,30 @@ meta_run (void)
 void
 meta_quit (MetaExitCode code)
 {
-  if (g_main_loop_is_running (meta_main_loop))
+  MetaContext *context;
+
+  if (meta_main_loop && g_main_loop_is_running (meta_main_loop))
     {
       meta_exit_code = code;
       g_main_loop_quit (meta_main_loop);
     }
+
+  context = meta_get_context_temporary ();
+  if (context)
+    {
+      if (code == META_EXIT_SUCCESS)
+        {
+          meta_context_terminate (context);
+        }
+      else
+        {
+          GError *error;
+
+          error = g_error_new (G_IO_ERROR,  G_IO_ERROR_FAILED,
+                               "Exited with failure status");
+          meta_context_terminate_with_error (context, error);
+        }
+    }
 }
 
 MetaExitCode

src/core/meta-context.c

@@ -354,6 +354,24 @@ meta_context_finalize (GObject *object)
   G_OBJECT_CLASS (meta_context_parent_class)->finalize (object);
 }
 
+/*
+ * NOTE!
+ *
+ * This global singletone is a temporary stop-gap solution
+ * to allow migrating to MetaContext in smaller steps. It will
+ * be removed later in this series of changes.
+ */
+static MetaContext *_context_temporary;
+
+MetaContext *
+meta_get_context_temporary (void);
+
+MetaContext *
+meta_get_context_temporary (void)
+{
+  return _context_temporary;
+}
+
 static void
 meta_context_class_init (MetaContextClass *klass)
 {
@@ -379,6 +397,9 @@ meta_context_class_init (MetaContextClass *klass)
 static void
 meta_context_init (MetaContext *context)
 {
+  g_assert (!_context_temporary);
+  _context_temporary = context;
+
   if (!setlocale (LC_ALL, ""))
     g_warning ("Locale not understood by C library");
   bindtextdomain (GETTEXT_PACKAGE, MUTTER_LOCALEDIR);