[gtk+/wip/carlosg/event-delivery] scrolledwindow: Avoid critical when removing source

[Timm Bäder <baedert src gnome org>]

commit 4c553391343c9e84a053033ed26206916970adc2
Author: Timm Bäder <mail baedert org>
Date:   Wed May 10 10:55:50 2017 +0200

    scrolledwindow: Avoid critical when removing source
    
    Make sure indicator->conceil_timer is actually set before trying to
    remove it.

 gtk/gtkscrolledwindow.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 884779d..e2400a9 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -3821,7 +3821,8 @@ indicator_set_fade (Indicator *indicator,
     {
       indicator->conceil_timer = g_timeout_add (INDICATOR_FADE_OUT_TIME, maybe_hide_indicator, indicator);
     }
-  if (!visible && gtk_widget_get_mapped (indicator->scrollbar))
+  if (!visible && gtk_widget_get_mapped (indicator->scrollbar) &&
+      indicator->conceil_timer != 0)
     {
       g_source_remove (indicator->conceil_timer);
       indicator->conceil_timer = 0;