coverity#1209861 untaint image data

Change-Id: Ib35d4a007c276aba45925ac281fff160bf07f9fe

vcl/unx/generic/dtrans/bmp.cxx

@@ -453,9 +453,21 @@ void PixmapHolder::setBitmapDataPalette( const sal_uInt8* pData, XImage* pImage
     {
         if( m_aInfo.c_class != TrueColor )
         {
-            aPalette[i].red     = ((unsigned short)pData[42 + i*4]) << 8 | ((unsigned short)pData[42 + i*4]);
-            aPalette[i].green   = ((unsigned short)pData[41 + i*4]) << 8 | ((unsigned short)pData[41 + i*4]);
-            aPalette[i].blue    = ((unsigned short)pData[40 + i*4]) << 8 | ((unsigned short)pData[40 + i*4]);
+            //This is untainted data which comes from a controlled source
+            //so, using a byte-swapping pattern which coverity doesn't
+            //detect as such
+            //http://security.coverity.com/blog/2014/Apr/on-detecting-heartbleed-with-static-analysis.html
+            aPalette[i].red = ((unsigned short)pData[42 + i*4]);
+            aPalette[i].red <<= 8;
+            aPalette[i].red |= ((unsigned short)pData[42 + i*4]);
+
+            aPalette[i].green = ((unsigned short)pData[41 + i*4]);
+            aPalette[i].green <<= 8;
+            aPalette[i].green |= ((unsigned short)pData[41 + i*4]);
+
+            aPalette[i].blue = ((unsigned short)pData[40 + i*4]);
+            aPalette[i].blue <<= 8;
+            aPalette[i].blue |= ((unsigned short)pData[40 + i*4]);
             XAllocColor( m_pDisplay, m_aColormap, aPalette+i );
         }
         else