babl: fix LUT from grayscale to RGBA images.

Images from "Y'A" to "R'G'B'A" for instance would end up completely
transparent because we were not reporting the alpha channel from the
source to destination buffer.

diff --git a/babl/babl-fish-path.c b/babl/babl-fish-path.c
index 808381cad5fee1b4b986f3e7d4c69caf62ba86bd..a4b002af080447623322848fdabbba1be526f3ed 100644 (file)
--- a/babl/babl-fish-path.c
+++ b/babl/babl-fish-path.c
@@ -200,8 +200,10 @@ static inline int _do_lut (uint32_t *lut,
           uint32_t *dst = (uint32_t*)destination;
           while (n--)
           {
-             *dst = lut[*src++];
-             dst++;
+            uint16_t col = *src++;
+            *dst = lut[col & 0xff];
+            *dst |= (((uint32_t) (col & 0xff00)) << 16);
+            dst++;
           }
         }
         else if (source_bpp == 2 && dest_bpp == 2)