[gtk] label: Skip updating link state if we have no layout

[Timm Bäder <baedert src gnome org>]

commit 563b80d43491223aed3512c31eaa8e069ea3c076
Author: Timm Bäder <mail baedert org>
Date:   Fri Jan 11 17:46:12 2019 +0100

    label: Skip updating link state if we have no layout
    
    This can happen whenever the ::activate-link handler sets different
    markup on the label, causing all links to be recreated. In this case,
    the GtkLabelLink* passed to emit_activate_link is garbage after the
    g_signal_emit call and we shouldn't try to do anything with it.
    
    Fixes #1498

 gtk/gtklabel.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/gtk/gtklabel.c b/gtk/gtklabel.c
index 7ca9ad7cf3..1d4223aada 100644
--- a/gtk/gtklabel.c
+++ b/gtk/gtklabel.c
@@ -6173,6 +6173,11 @@ emit_activate_link (GtkLabel     *label,
   GtkStateFlags state;
 
   g_signal_emit (label, signals[ACTIVATE_LINK], 0, link->uri, &handled);
+
+  /* signal handler might have invalidated the layout */
+  if (!priv->layout)
+    return;
+
   if (handled && priv->track_links && !link->visited &&
       priv->select_info && priv->select_info->links)
     {