From 6664c12278130ad32f7a27bfad01c6fc9691653a Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Wed, 17 Mar 2010 10:06:40 +0100
Subject: Fix up empty region checks in canvas operations

We rely on not passing on empty rects to the drawing operations by
checking for empty regions and exiting early. However the checks
were wrongly using pixman_region32_n_rects(region) == 0, whereas
we should be using pixman_region32_not_empty().
---
 common/cairo_canvas.c |  2 +-
 common/canvas_base.c  | 18 +++++++++---------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/common/cairo_canvas.c b/common/cairo_canvas.c
index 9e29e17a..770ca4ff 100644
--- a/common/cairo_canvas.c
+++ b/common/cairo_canvas.c
@@ -675,7 +675,7 @@ static void canvas_draw_text(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceCl
 
     canvas_clip_pixman(&canvas->base, &dest_region, clip);
 
-    if (pixman_region32_n_rects(&dest_region) == 0) {
+    if (!pixman_region32_not_empty(&dest_region)) {
         touch_brush(&canvas->base, &text->fore_brush);
         touch_brush(&canvas->base, &text->back_brush);
         pixman_region32_fini(&dest_region);
diff --git a/common/canvas_base.c b/common/canvas_base.c
index beedae95..aecc56e2 100644
--- a/common/canvas_base.c
+++ b/common/canvas_base.c
@@ -1976,7 +1976,7 @@ static void canvas_draw_fill(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceCl
                                  ROP_INPUT_BRUSH,
                                  ROP_INPUT_DEST);
 
-    if (rop == SPICE_ROP_NOOP || pixman_region32_n_rects(&dest_region) == 0) {
+    if (rop == SPICE_ROP_NOOP || !pixman_region32_not_empty(&dest_region)) {
         touch_brush(canvas, &fill->brush);
         pixman_region32_fini(&dest_region);
         return;
@@ -2007,7 +2007,7 @@ static void canvas_draw_copy(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceCl
                                  ROP_INPUT_SRC,
                                  ROP_INPUT_DEST);
 
-    if (rop == SPICE_ROP_NOOP || pixman_region32_n_rects(&dest_region) == 0) {
+    if (rop == SPICE_ROP_NOOP || !pixman_region32_not_empty(&dest_region)) {
         canvas_touch_image(canvas, copy->src_bitmap);
         pixman_region32_fini(&dest_region);
         return;
@@ -2120,7 +2120,7 @@ static void canvas_draw_alpha_blend(SpiceCanvas *spice_canvas, SpiceRect *bbox,
     canvas_clip_pixman(canvas, &dest_region, clip);
 
     if (alpha_blend->alpha == 0 ||
-        pixman_region32_n_rects(&dest_region) == 0) {
+        !pixman_region32_not_empty(&dest_region)) {
         canvas_touch_image(canvas, alpha_blend->src_bitmap);
         pixman_region32_fini(&dest_region);
         return;
@@ -2177,7 +2177,7 @@ static void canvas_draw_opaque(SpiceCanvas *spice_canvas, SpiceRect *bbox, Spice
                                  ROP_INPUT_BRUSH,
                                  ROP_INPUT_SRC);
 
-    if (rop == SPICE_ROP_NOOP || pixman_region32_n_rects(&dest_region) == 0) {
+    if (rop == SPICE_ROP_NOOP || !pixman_region32_not_empty(&dest_region)) {
         canvas_touch_image(canvas, opaque->src_bitmap);
         touch_brush(canvas, &opaque->brush);
         pixman_region32_fini(&dest_region);
@@ -2231,7 +2231,7 @@ static void canvas_draw_blend(SpiceCanvas *spice_canvas, SpiceRect *bbox, SpiceC
                                  ROP_INPUT_SRC,
                                  ROP_INPUT_DEST);
 
-    if (rop == SPICE_ROP_NOOP || pixman_region32_n_rects(&dest_region) == 0) {
+    if (rop == SPICE_ROP_NOOP || !pixman_region32_not_empty(&dest_region)) {
         canvas_touch_image(canvas, blend->src_bitmap);
         pixman_region32_fini(&dest_region);
         return;
@@ -2305,7 +2305,7 @@ static void canvas_draw_blackness(SpiceCanvas *spice_canvas, SpiceRect *bbox, Sp
     canvas_mask_pixman(canvas, &dest_region, &blackness->mask,
                        bbox->left, bbox->top);
 
-    if (pixman_region32_n_rects(&dest_region) == 0) {
+    if (!pixman_region32_not_empty(&dest_region)) {
         pixman_region32_fini (&dest_region);
         return;
     }
@@ -2334,7 +2334,7 @@ static void canvas_draw_whiteness(SpiceCanvas *spice_canvas, SpiceRect *bbox, Sp
     canvas_mask_pixman(canvas, &dest_region, &whiteness->mask,
                        bbox->left, bbox->top);
 
-    if (pixman_region32_n_rects(&dest_region) == 0) {
+    if (!pixman_region32_not_empty(&dest_region)) {
         pixman_region32_fini(&dest_region);
         return;
     }
@@ -2362,7 +2362,7 @@ static void canvas_draw_invers(SpiceCanvas *spice_canvas, SpiceRect *bbox, Spice
     canvas_mask_pixman(canvas, &dest_region, &invers->mask,
                        bbox->left, bbox->top);
 
-    if (pixman_region32_n_rects(&dest_region) == 0) {
+    if (!pixman_region32_not_empty(&dest_region)) {
         pixman_region32_fini(&dest_region);
         return;
     }
@@ -2677,7 +2677,7 @@ static void canvas_draw_stroke(SpiceCanvas *spice_canvas, SpiceRect *bbox,
 
     canvas_clip_pixman(canvas, &gc.dest_region, clip);
 
-    if (pixman_region32_n_rects(&gc.dest_region) == 0) {
+    if (!pixman_region32_not_empty(&gc.dest_region)) {
         touch_brush(canvas, &stroke->brush);
         pixman_region32_fini(&gc.dest_region);
         return;
-- 
cgit