winex11.drv: Store if a bitmap is top-down in X_PHYSBITMAP.

GetObject() is supposed to return the absolute height, and there's no other
way to retrieve this information after the bitmap is created.

dlls/winex11.drv/bitblt.c

@@ -1308,7 +1308,7 @@ static BOOL client_side_dib_copy( X11DRV_PDEVICE *physDevSrc, INT xSrc, INT ySrc
 
     bytesToCopy = width * bytesPerPixel;
 
-    if (srcDib.dsBmih.biHeight < 0)
+    if (physDevSrc->bitmap->topdown)
     {
       srcPtr = &physDevSrc->bitmap->base[ySrc*srcDib.dsBm.bmWidthBytes + xSrc*bytesPerPixel];
       srcRowOffset = srcDib.dsBm.bmWidthBytes;
@@ -1319,7 +1319,7 @@ static BOOL client_side_dib_copy( X11DRV_PDEVICE *physDevSrc, INT xSrc, INT ySrc
         + xSrc*bytesPerPixel];
       srcRowOffset = -srcDib.dsBm.bmWidthBytes;
     }
-    if (dstDib.dsBmih.biHeight < 0)
+    if (physDevDst->bitmap->topdown)
     {
       dstPtr = &physDevDst->bitmap->base[yDst*dstDib.dsBm.bmWidthBytes + xDst*bytesPerPixel];
       dstRowOffset = dstDib.dsBm.bmWidthBytes;

dlls/winex11.drv/dib.c

@@ -4726,12 +4726,17 @@ HBITMAP CDECL X11DRV_CreateDIBSection( X11DRV_PDEVICE *physDev, HBITMAP hbitmap,
 {
     X_PHYSBITMAP *physBitmap;
     DIBSECTION dib;
+    WORD bpp, compr;
+    LONG w, h;
 #ifdef HAVE_LIBXXSHM
     int major, minor;
     Bool pixmaps;
 #endif
 
+    DIB_GetBitmapInfo( &bmi->bmiHeader, &w, &h, &bpp, &compr );
+
     if (!(physBitmap = X11DRV_init_phys_bitmap( hbitmap ))) return 0;
+    if (h < 0) physBitmap->topdown = TRUE;
     physBitmap->status = DIB_Status_None;
 
     GetObjectW( hbitmap, sizeof(dib), &dib );

dlls/winex11.drv/x11drv.h

@@ -127,6 +127,7 @@ typedef struct
     int         *colorMap;          /* color map info */
     int          nColorMap;
     BOOL         trueColor;
+    BOOL         topdown;
     CRITICAL_SECTION lock;          /* GDI access lock */
     enum x11drv_shm_mode shm_mode;
 #ifdef HAVE_LIBXXSHM