From 390091cc24c364be39bbfdeec4e6dc0fee724568 Mon Sep 17 00:00:00 2001
From: Artur Wieczorek <artwik@wp.pl>
Date: Sun, 17 Jan 2016 16:19:52 +0100
Subject: [PATCH] Don't set alpha flag for wxBitmaps with depth < 32 bpp
 (wxMSW).

Flag indicating that bitmap contains alpha channel can be set only for 32 bpp bitmap.
---
 src/msw/bitmap.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/msw/bitmap.cpp b/src/msw/bitmap.cpp
index 16fe42092c..780d12cb74 100644
--- a/src/msw/bitmap.cpp
+++ b/src/msw/bitmap.cpp
@@ -1204,7 +1204,13 @@ wxDC *wxBitmap::GetSelectedInto() const
 void wxBitmap::UseAlpha(bool use)
 {
     if ( GetBitmapData() )
+    {
+        // Only 32bpp bitmaps can contain alpha channel.
+        if ( use && GetBitmapData()->m_depth < 32 )
+            use = false;
+
         GetBitmapData()->m_hasAlpha = use;
+    }
 }
 
 bool wxBitmap::HasAlpha() const