Don't copy unused bits to an alpha channel

This bug was identified by cairo's rgb24-ignore-alpha test which
blends RGB24 over ARGB32 and notices that "alpha" values are
making it from the source to the destination.

diff --git a/pixman/pixman-pict.c b/pixman/pixman-pict.c
index b8b7b76..c7d73fc 100644 (file)
--- a/pixman/pixman-pict.c
+++ b/pixman/pixman-pict.c
@@ -1778,7 +1778,6 @@ pixman_image_composite (pixman_op_t      op,
                    break;
                case PIXMAN_x8r8g8b8:
                    switch (pDst->bits.format) {
-                   case PIXMAN_a8r8g8b8:
                    case PIXMAN_x8r8g8b8:
 #ifdef USE_MMX
                        if (pixman_have_mmx())
@@ -1790,7 +1789,6 @@ pixman_image_composite (pixman_op_t      op,
                    }
                case PIXMAN_x8b8g8r8:
                    switch (pDst->bits.format) {
-                   case PIXMAN_a8b8g8r8:
                    case PIXMAN_x8b8g8r8:
 #ifdef USE_MMX
                        if (pixman_have_mmx())