From 1a965c03fefe03debb05130f0bfa223f59c60424 Mon Sep 17 00:00:00 2001
From: Paul Cornett <paulcor@bullseye.com>
Date: Fri, 30 May 2014 16:29:13 +0000
Subject: [PATCH] Fix X 'BadPixmap' crash in Blit() with mask when GTK+ <=
 2.16, closes #16303

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76626 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 docs/changes.txt     |  1 +
 src/gtk/dcclient.cpp | 14 ++++++++------
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/docs/changes.txt b/docs/changes.txt
index 20e5bc2354..eb0258d46b 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -625,6 +625,7 @@ wxGTK:
   special folder from combobox
 - Fix wxSystemSettings::GetColour() returning transparent colors with GTK3.
 - Fix setting client data when adding items to a sorted wxListBox.
+- Fix X 'BadPixmap' crash in wxDC::Blit() with mask when GTK+ <= 2.16.
 
 wxMSW:
 
diff --git a/src/gtk/dcclient.cpp b/src/gtk/dcclient.cpp
index 2c4a716964..7af0853973 100644
--- a/src/gtk/dcclient.cpp
+++ b/src/gtk/dcclient.cpp
@@ -1199,9 +1199,8 @@ void wxWindowDCImpl::DoDrawBitmap( const wxBitmap &bitmap,
         gdk_gc_set_clip_region(use_gc, clipRegion);
 
         // Notice that we can only release the mask now, we can't do it before
-        // the calls to gdk_draw_xxx() above as they crash with X error with
-        // GTK+ up to 2.20.1 (i.e. it works with 2.20 but is known to not work
-        // with 2.16.1 and below).
+        // the calls to gdk_draw_xxx() above as they crash with BadPixmap X
+        // error with GTK+ 2.16 and earlier.
         if (mask_new)
             g_object_unref(mask_new);
     }
@@ -1311,6 +1310,7 @@ bool wxWindowDCImpl::DoBlit( wxCoord xdest, wxCoord ydest,
 
     GdkGC* const use_gc = m_penGC;
 
+    GdkPixmap* mask_new = NULL;
     if (mask)
     {
         int srcMask_x = src_x;
@@ -1320,7 +1320,6 @@ bool wxWindowDCImpl::DoBlit( wxCoord xdest, wxCoord ydest,
             srcMask_x = source->LogicalToDeviceX(xsrcMask);
             srcMask_y = source->LogicalToDeviceY(ysrcMask);
         }
-        GdkPixmap* mask_new = NULL;
         if (isScaled)
         {
             mask = ScaleMask(mask, srcMask_x, srcMask_y,
@@ -1343,8 +1342,6 @@ bool wxWindowDCImpl::DoBlit( wxCoord xdest, wxCoord ydest,
         }
         gdk_gc_set_clip_mask(use_gc, mask);
         gdk_gc_set_clip_origin(use_gc, dst_x - srcMask_x, dst_y - srcMask_y);
-        if (mask_new)
-            g_object_unref(mask_new);
     }
 
     GdkPixmap* pixmap = NULL;
@@ -1385,7 +1382,12 @@ bool wxWindowDCImpl::DoBlit( wxCoord xdest, wxCoord ydest,
     if (pixmap)
         g_object_unref(pixmap);
     if (mask)
+    {
         gdk_gc_set_clip_region(use_gc, clipRegion);
+        // see comment at end of DoDrawBitmap()
+        if (mask_new)
+            g_object_unref(mask_new);
+    }
 
     return true;
 }