[gtk/wip/carlosg/startup-notification-fixes: 1/2] gtkapplication: Stash DESKTOP_STARTUP_ID on a constructor

[Carlos Garnacho <carlosg src gnome org>]

commit 224a53d97b53da9cc9d08e1675ae860d7e49f8b6
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Mar 17 16:04:51 2019 +0100

    gtkapplication: Stash DESKTOP_STARTUP_ID on a constructor
    
    It might be too late to do it at GtkApplication::add_platform_data time,
    since the envvar may be consumed earlier on if gdk_display_open() happened
    to be called before (eg. through gtk_get_option_group(TRUE)).
    
    Stash the envvar in a constructor function, so its ensured to happen before
    it can get consumed.
    
    Closes: https://gitlab.gnome.org/GNOME/gtk/issues/1754

 gtk/gtkapplication.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtkapplication.c b/gtk/gtkapplication.c
index 5d26f07088..d0f32a8638 100644
--- a/gtk/gtkapplication.c
+++ b/gtk/gtkapplication.c
@@ -28,6 +28,8 @@
 #include <unistd.h>
 #endif
 
+#include "gdk/gdkconstructor.h"
+
 #include "gtkapplicationprivate.h"
 #include "gtkclipboardprivate.h"
 #include "gtkmarshalers.h"
@@ -166,6 +168,21 @@ struct _GtkApplicationPrivate
 
 G_DEFINE_TYPE_WITH_PRIVATE (GtkApplication, gtk_application, G_TYPE_APPLICATION)
 
+#ifdef G_HAS_CONSTRUCTORS
+#ifdef G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA
+#pragma G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(stash_desktop_startup_id)
+#endif
+G_DEFINE_CONSTRUCTOR(stash_desktop_startup_id)
+#endif
+
+static const char *desktop_startup_id = NULL;
+
+static void
+stash_desktop_startup_id (void)
+{
+  desktop_startup_id = g_getenv ("DESKTOP_STARTUP_ID");
+}
+
 static gboolean
 gtk_application_focus_in_event_cb (GtkWindow      *window,
                                    GdkEventFocus  *event,
@@ -338,8 +355,6 @@ static void
 gtk_application_add_platform_data (GApplication    *application,
                                    GVariantBuilder *builder)
 {
-  const gchar *startup_id;
-
   /* This is slightly evil.
    *
    * We don't have an impl here because we're remote so we can't figure
@@ -347,11 +362,9 @@ gtk_application_add_platform_data (GApplication    *application,
    *
    * So we do all the things... which currently is just one thing.
    */
-  startup_id = getenv ("DESKTOP_STARTUP_ID");
-
-  if (startup_id && g_utf8_validate (startup_id, -1, NULL))
+  if (desktop_startup_id && g_utf8_validate (desktop_startup_id, -1, NULL))
     g_variant_builder_add (builder, "{sv}", "desktop-startup-id",
-                           g_variant_new_string (startup_id));
+                           g_variant_new_string (desktop_startup_id));
 }
 
 static void
@@ -380,6 +393,10 @@ gtk_application_init (GtkApplication *application)
   application->priv->muxer = gtk_action_muxer_new ();
 
   application->priv->accels = gtk_application_accels_new ();
+
+#ifndef G_HAS_CONSTRUCTORS
+  stash_desktop_startup_id ();
+#endif
 }
 
 static void