[cairo] [PATCH 1/4] image: _cairo_image_surface_fixup_unbounded_boxes() bug fix

[Taekyun Kim]

From: Taekyun Kim <tkq.kim at samsung.com>

Even if boxes contains zero or single boxes, we cannot assume
that extents->bounded is tight. So we have to make extents tight
before giving it to _cairo_image_surface_fixup_unbounded().
---
 src/cairo-image-surface.c |   26 ++++++++++++++++++++++++--
 1 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/cairo-image-surface.c b/src/cairo-image-surface.c
index a2345b2..21ede2c 100644
--- a/src/cairo-image-surface.c
+++ b/src/cairo-image-surface.c
@@ -1778,8 +1778,30 @@ _cairo_image_surface_fixup_unbounded_boxes (cairo_image_surface_t *dst,
     struct _cairo_boxes_chunk *chunk;
     int i;
 
-    if (boxes->num_boxes <= 1 && clip_region == NULL)
-	return _cairo_image_surface_fixup_unbounded (dst, extents, NULL);
+    if (clip_region == NULL) {
+	cairo_composite_rectangles_t tight_extents;
+
+	if (boxes->num_boxes == 0) {
+	    tight_extents = *extents;
+	    tight_extents.bounded.x = 0;
+	    tight_extents.bounded.y = 0;
+	    tight_extents.bounded.width = 0;
+	    tight_extents.bounded.height = 0;
+
+	    return _cairo_image_surface_fixup_unbounded (dst, &tight_extents, NULL);
+	} else if (boxes->num_boxes == 1) {
+	    box = boxes->chunks.base[0];
+	    tight_extents = *extents;
+	    tight_extents.bounded.x = _cairo_fixed_integer_round_down(box.p1.x);
+	    tight_extents.bounded.y = _cairo_fixed_integer_round_down(box.p1.y);
+	    tight_extents.bounded.width =
+		_cairo_fixed_integer_round_down(box.p2.x) - tight_extents.bounded.x;
+	    tight_extents.bounded.height =
+		_cairo_fixed_integer_round_down(box.p2.y) - tight_extents.bounded.y;
+
+	    return _cairo_image_surface_fixup_unbounded (dst, &tight_extents, NULL);
+	}
+    }
 
     _cairo_boxes_init (&clear);
 
-- 
1.7.1