[gimp/gimp-2-10] app: fix a super secret segfault

[Ell <ell src gnome org>]

commit 5f97141ba69d834b26f4ff41f43d633d8fd35033
Author: Ell <ell_se yahoo com>
Date:   Thu Jan 30 18:24:44 2020 +0200

    app: fix a super secret segfault
    
    (cherry picked from commit 2145f4301c0dea6dbc5c97635795b330c53efd03)

 app/dialogs/lebl-dialog.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/app/dialogs/lebl-dialog.c b/app/dialogs/lebl-dialog.c
index 61ce585ee4..53bd492123 100644
--- a/app/dialogs/lebl-dialog.c
+++ b/app/dialogs/lebl-dialog.c
@@ -162,7 +162,10 @@ inv_show_status (void)
 static gboolean
 inv_draw (gpointer data)
 {
-        gtk_widget_queue_draw (data);
+        inv_draw_idle = 0;
+
+        if (geginv)
+                gtk_widget_queue_draw (data);
 
         return FALSE;
 }