[gtk+] Fix gdk_device_get_history() for the core pointer

[Michael Natterer <mitch src gnome org>]

commit 659776ce35b4894c5217325978aa48a79689d669
Author: Michael Natterer <mitch gimp org>
Date:   Thu Sep 17 11:38:14 2009 +0200

    Fix gdk_device_get_history() for the core pointer
    
    When filtering out the events for "window" from the events we got for
    our "impl_window", don't forget to adjust the returned number of
    events because it might be smaller than what XGetMotionEvents has
    returned, and free coords we allocated too much. Also if we filtered
    away *all* events, return FALSE and get rid of the allocated history
    entirely. Together fixes all sorts of mishehavior when painting in
    GIMP, from coords going wild to plain crashes and infinite loops.

 gdk/x11/gdkinput.c |   28 +++++++++++++++++++++++-----
 1 files changed, 23 insertions(+), 5 deletions(-)
---
diff --git a/gdk/x11/gdkinput.c b/gdk/x11/gdkinput.c
index c33f09c..6c3cdbb 100644
--- a/gdk/x11/gdkinput.c
+++ b/gdk/x11/gdkinput.c
@@ -266,7 +266,6 @@ gdk_device_get_history  (GdkDevice         *device,
   GdkWindow *impl_window;
   gboolean result = FALSE;
   int tmp_n_events = 0;
-  int i, j;
 
   g_return_val_if_fail (GDK_WINDOW_IS_X11 (window), FALSE);
 
@@ -284,9 +283,12 @@ gdk_device_get_history  (GdkDevice         *device,
       if (xcoords)
 	{
 	  GdkWindowObject *priv = (GdkWindowObject *)window;
+          int i, j;
+
 	  coords = _gdk_device_allocate_history (device, tmp_n_events);
 	  j = 0;
-	  for (i=0; i<tmp_n_events; i++)
+
+	  for (i = 0; i < tmp_n_events; i++)
 	    {
 	      if (impl_coord_in_window (window, xcoords[i].x, xcoords[i].y))
 		{
@@ -299,16 +301,32 @@ gdk_device_get_history  (GdkDevice         *device,
 
 	  XFree (xcoords);
 
-	  result = TRUE;
+          /* free the events we allocated too much */
+          for (i = j; i < tmp_n_events; i++)
+            {
+              g_free (coords[i]);
+              coords[i] = NULL;
+            }
+
+          tmp_n_events = j;
+
+          if (tmp_n_events > 0)
+            {
+              result = TRUE;
+            }
+          else
+            {
+              gdk_device_free_history (coords, tmp_n_events);
+              coords = NULL;
+            }
 	}
-      else
-	result = FALSE;
     }
   else
     result = _gdk_device_get_history (device, window, start, stop, &coords, &tmp_n_events);
 
   if (n_events)
     *n_events = tmp_n_events;
+
   if (events)
     *events = coords;
   else if (coords)