[PATCH] desktop-shell: Fix black edges on scaled desktop pattern

[Bill Spitzak]

Filter sampling outside the source image can leak black into the edges of the
desktop image. This is most easily seen by scaling the default tiled image
with this weston.ini:

	# no background-image and no background-color
	background-type=scale-crop
---
 clients/desktop-shell.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/clients/desktop-shell.c b/clients/desktop-shell.c
index 4880888..e121cc7 100644
--- a/clients/desktop-shell.c
+++ b/clients/desktop-shell.c
@@ -724,6 +724,7 @@ background_draw(struct widget *widget, void *data)
 		case BACKGROUND_SCALE:
 			cairo_matrix_init_scale(&matrix, sx, sy);
 			cairo_pattern_set_matrix(pattern, &matrix);
+			cairo_pattern_set_extend(pattern, CAIRO_EXTEND_PAD);
 			break;
 		case BACKGROUND_SCALE_CROP:
 			s = (sx < sy) ? sx : sy;
@@ -733,6 +734,7 @@ background_draw(struct widget *widget, void *data)
 			cairo_matrix_init_translate(&matrix, tx, ty);
 			cairo_matrix_scale(&matrix, s, s);
 			cairo_pattern_set_matrix(pattern, &matrix);
+			cairo_pattern_set_extend(pattern, CAIRO_EXTEND_PAD);
 			break;
 		case BACKGROUND_TILE:
 			cairo_pattern_set_extend(pattern, CAIRO_EXTEND_REPEAT);
-- 
1.7.9.5