bug 974575 - support color glyphs in cairo_image_surface's _composite_glyphs function. r=jrmuizel

gfx/cairo/cairo/src/cairo-image-surface.c

@@ -3958,16 +3958,6 @@ _composite_glyphs (void				*closure,
     cairo_status_t status;
     int i;
 
-    if (pattern != NULL) {
-	src = _pixman_image_for_pattern (pattern, FALSE, extents, &src_x, &src_y);
-	src_x -= dst_x;
-	src_y -= dst_y;
-    } else {
-	src = _pixman_white_image ();
-    }
-    if (unlikely (src == NULL))
-	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
-
     memset (glyph_cache, 0, sizeof (glyph_cache));
     status = CAIRO_STATUS_SUCCESS;
 
@@ -4018,17 +4008,43 @@ _composite_glyphs (void				*closure,
 	    if (y2 > extents->y + extents->height)
 		y2 = extents->y + extents->height;
 
-	    pixman_image_composite32 (pixman_op,
-                                      src, glyph_surface->pixman_image, dst,
-                                      x1 + src_x,  y1 + src_y,
-                                      x1 - x, y1 - y,
-                                      x1 - dst_x, y1 - dst_y,
-                                      x2 - x1, y2 - y1);
+	    if (glyph_surface->format == CAIRO_FORMAT_A8 ||
+	        glyph_surface->format == CAIRO_FORMAT_A1)
+	    {
+		if (unlikely (src == NULL)) {
+		    if (pattern != NULL) {
+			src = _pixman_image_for_pattern (pattern, FALSE, extents, &src_x, &src_y);
+			src_x -= dst_x;
+			src_y -= dst_y;
+		    } else {
+			src = _pixman_white_image ();
+		    }
+		    if (unlikely (src == NULL)) {
+			status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
+			break;
+		    }
+		}
+
+		pixman_image_composite32 (pixman_op,
+					  src, glyph_surface->pixman_image, dst,
+					  x1 + src_x, y1 + src_y,
+					  x1 - x, y1 - y,
+					  x1 - dst_x, y1 - dst_y,
+					  x2 - x1, y2 - y1);
+	    } else {
+		pixman_image_composite32 (pixman_op,
+					  glyph_surface->pixman_image, NULL, dst,
+					  x1 - x, y1 - y,
+					  0, 0,
+					  x1 - dst_x, y1 - dst_y,
+					  x2 - x1, y2 - y1);
+	    }
 	}
     }
     _cairo_scaled_font_thaw_cache (info->font);
 
-    pixman_image_unref (src);
+    if (src != NULL)
+	pixman_image_unref (src);
 
     return status;
 }