[gtk+/gtk-3-20] Docs: Clarify life cycle issue

[Rico Tzschichholz <ricotz src gnome org>]

commit b893b62d7a7b3014edf408df7e709e7cb110bac5
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed May 11 13:25:15 2016 -0400

    Docs: Clarify life cycle issue
    
    gtk_gesture_get_last_event() wasn't very clear about how long
    it is safe to use the returned pointer.
    
    (cherry picked from commit c891ceb31df1fb16c7727be46cee4d8a9fc0b447)

 gtk/gtkgesture.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkgesture.c b/gtk/gtkgesture.c
index 8eaa518..8f92f1d 100644
--- a/gtk/gtkgesture.c
+++ b/gtk/gtkgesture.c
@@ -1274,6 +1274,10 @@ gtk_gesture_get_last_updated_sequence (GtkGesture *gesture)
  *
  * Returns the last event that was processed for @sequence.
  *
+ * Note that the returned pointer is only valid as long as the @sequence
+ * is still interpreted by the @gesture. If in doubt, you should make
+ * a copy of the event.
+ *
  * Returns: (transfer none) (nullable): The last event from @sequence
  **/
 const GdkEvent *