From ffd2857571672ceb01c716a9ae0f661d9fc5621b Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Wed, 1 Apr 2015 14:15:11 +0200
Subject: [PATCH] Fix vertical alpha adjustment in
 wxPixelData<wxImage>::Offset().

Handle "y" parameter correctly when offsetting m_pAlpha, it was just ignored
before, i.e. Offset(x, y) and OffsetY(y) always behaved as if y were 1.
---
 include/wx/rawbmp.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/wx/rawbmp.h b/include/wx/rawbmp.h
index 1f89e5acc2..fae330a7e3 100644
--- a/include/wx/rawbmp.h
+++ b/include/wx/rawbmp.h
@@ -372,7 +372,7 @@ struct wxPixelDataOut<wxImage>
             {
                 m_pRGB += data.GetRowStride()*y + PixelFormat::SizePixel*x;
                 if ( m_pAlpha )
-                    m_pAlpha += data.GetWidth() + x;
+                    m_pAlpha += data.GetWidth()*y + x;
             }
 
             // move x pixels to the right (again, no row wrapping)
@@ -388,7 +388,7 @@ struct wxPixelDataOut<wxImage>
             {
                 m_pRGB += data.GetRowStride()*y;
                 if ( m_pAlpha )
-                    m_pAlpha += data.GetWidth();
+                    m_pAlpha += data.GetWidth()*y;
             }
 
             // go to the given position