Review users of cairo_rectangle_int_t for incorrect unsigned promotion.

Adrian Johnson discovered cases where we mistakenly compared the result
of unsigned arithmetic where we need signed quantities. Look for similar
cases in the users of cairo_rectangle_int_t.

1 files changed, 22 insertions, 21 deletions

diff --git a/src/cairo-clip.c b/src/cairo-clip.c
index 308da326..8a0d4db1 100644
--- a/src/cairo-clip.c
+++ b/src/cairo-clip.c
@@ -166,7 +166,8 @@ _cairo_clip_path_intersect_to_rectangle (cairo_clip_path_t       *clip_path,
         _cairo_traps_fini (&traps);
 
         _cairo_box_round_to_rectangle (&extents, &extents_rect);
-        _cairo_rectangle_intersect (rectangle, &extents_rect);
+        if (! _cairo_rectangle_intersect (rectangle, &extents_rect))
+	    return CAIRO_STATUS_SUCCESS;
 
         clip_path = clip_path->prev;
     }
@@ -178,6 +179,9 @@ cairo_status_t
 _cairo_clip_intersect_to_rectangle (cairo_clip_t            *clip,
 				    cairo_rectangle_int_t *rectangle)
 {
+    cairo_status_t status;
+    cairo_bool_t is_empty;
+
     if (!clip)
 	return CAIRO_STATUS_SUCCESS;
 
@@ -187,8 +191,6 @@ _cairo_clip_intersect_to_rectangle (cairo_clip_t            *clip,
     }
 
     if (clip->path) {
-        cairo_status_t status;
-
         status = _cairo_clip_path_intersect_to_rectangle (clip->path,
                                                           rectangle);
         if (status)
@@ -196,7 +198,6 @@ _cairo_clip_intersect_to_rectangle (cairo_clip_t            *clip,
     }
 
     if (clip->has_region) {
-	cairo_status_t status = CAIRO_STATUS_SUCCESS;
 	cairo_region_t intersection;
 
 	_cairo_region_init_rect (&intersection, rectangle);
@@ -214,7 +215,7 @@ _cairo_clip_intersect_to_rectangle (cairo_clip_t            *clip,
     }
 
     if (clip->surface)
-	_cairo_rectangle_intersect (rectangle, &clip->surface_rect);
+	is_empty = _cairo_rectangle_intersect (rectangle, &clip->surface_rect);
 
     return CAIRO_STATUS_SUCCESS;
 }
@@ -421,7 +422,7 @@ _cairo_clip_intersect_mask (cairo_clip_t      *clip,
     cairo_pattern_union_t pattern;
     cairo_box_t extents;
     cairo_rectangle_int_t surface_rect, target_rect;
-    cairo_surface_t *surface;
+    cairo_surface_t *surface = NULL;
     cairo_status_t status;
 
     if (clip->all_clipped)
@@ -434,22 +435,21 @@ _cairo_clip_intersect_mask (cairo_clip_t      *clip,
     _cairo_traps_extents (traps, &extents);
     _cairo_box_round_to_rectangle (&extents, &surface_rect);
 
-    if (clip->surface != NULL)
-	_cairo_rectangle_intersect (&surface_rect, &clip->surface_rect);
+    if (clip->surface != NULL) {
+	if (! _cairo_rectangle_intersect (&surface_rect, &clip->surface_rect))
+	    goto DONE;
+    }
 
     /* Intersect with the target surface rectangle so we don't use
      * more memory and time than we need to. */
     status = _cairo_surface_get_extents (target, &target_rect);
-    if (status == CAIRO_STATUS_SUCCESS)
-	_cairo_rectangle_intersect (&surface_rect, &target_rect);
+    if (status == CAIRO_STATUS_SUCCESS) {
+	if (! _cairo_rectangle_intersect (&surface_rect, &target_rect))
+	    goto DONE;
+    }
 
-    if (surface_rect.width == 0 || surface_rect.height == 0) {
-	surface = NULL;
-	status = CAIRO_STATUS_SUCCESS;
-	if (clip->surface != NULL)
-	    cairo_surface_destroy (clip->surface);
+    if (surface_rect.width == 0 || surface_rect.height == 0)
 	goto DONE;
-    }
 
     _cairo_pattern_init_solid (&pattern.solid, CAIRO_COLOR_WHITE,
 			       CAIRO_CONTENT_COLOR);
@@ -539,11 +539,10 @@ _cairo_clip_intersect_mask (cairo_clip_t      *clip,
 	    cairo_surface_destroy (surface);
 	    return status;
 	}
-
-	cairo_surface_destroy (clip->surface);
     }
 
  DONE:
+    cairo_surface_destroy (clip->surface);
     clip->surface = surface;
     clip->surface_rect = surface_rect;
     clip->serial = _cairo_surface_allocate_clip_serial (target);
@@ -740,10 +739,12 @@ _cairo_clip_int_rect_to_user (cairo_gstate_t *gstate,
 
     double x1 = clip_rect->x;
     double y1 = clip_rect->y;
-    double x2 = clip_rect->x + clip_rect->width;
-    double y2 = clip_rect->y + clip_rect->height;
+    double x2 = clip_rect->x + (int) clip_rect->width;
+    double y2 = clip_rect->y + (int) clip_rect->height;
 
-    _cairo_gstate_backend_to_user_rectangle (gstate, &x1, &y1, &x2, &y2, &is_tight);
+    _cairo_gstate_backend_to_user_rectangle (gstate,
+					     &x1, &y1, &x2, &y2,
+					     &is_tight);
 
     user_rect->x = x1;
     user_rect->y = y1;