From 72790218cb10e402a5774e87889cb6763c087c73 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Mon, 29 Jan 2018 15:36:21 +0100
Subject: [PATCH] Fix wrongly restoring clipping region in wxDCClipper

The change of 2a8c290e0de5e657f22a0c13817df65688b01345 was wrong as it
unconditionally restored m_oldClipRect in dtor, even when it was empty,
indicating that no clipping had been in effect when wxDCClipper was
constructed. This totally broke all the code using wxDCClipper, notably
generic wxListCtrl which wasn't repainted correctly at all.

Fix this by checking if the clipping rectangle is not empty before
restoring it, this should work as well as we can make it without having
GetClippingRegion() that could return an invalid region if no clipping
is in effect.

See #13834.

Closes #18066.
---
 include/wx/dc.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/wx/dc.h b/include/wx/dc.h
index dadbe793a3..38edf9da5f 100644
--- a/include/wx/dc.h
+++ b/include/wx/dc.h
@@ -1454,7 +1454,8 @@ public:
     ~wxDCClipper()
     {
         m_dc.DestroyClippingRegion();
-        m_dc.SetClippingRegion(m_oldClipRect);
+        if ( !m_oldClipRect.IsEmpty() )
+            m_dc.SetClippingRegion(m_oldClipRect);
     }
 
 private: