gtk: don't exit early in case gtk init fails

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
diff --git a/ui/gtk.c b/ui/gtk.c
index 126326a..df2a79e 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1917,12 +1917,19 @@
 #endif
 }
 
+static gboolean gtkinit;
+
 void gtk_display_init(DisplayState *ds, bool full_screen, bool grab_on_hover)
 {
     GtkDisplayState *s = g_malloc0(sizeof(*s));
     char *filename;
     GdkDisplay *window_display;
 
+    if (!gtkinit) {
+        fprintf(stderr, "gtk initialization failed\n");
+        exit(1);
+    }
+
     s->window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 #if GTK_CHECK_VERSION(3, 2, 0)
     s->vbox = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
@@ -2003,7 +2010,11 @@
 
 void early_gtk_display_init(int opengl)
 {
-    gtk_init(NULL, NULL);
+    gtkinit = gtk_init_check(NULL, NULL);
+    if (!gtkinit) {
+        /* don't exit yet, that'll break -help */
+        return;
+    }
 
     switch (opengl) {
     case -1: /* default */