michael@0: # HG changeset patch
michael@0: # User Robert O'Callahan <robert@ocallahan.org>
michael@0: # Date 1348618772 -43200
michael@0: # Node ID 55ccbc8d52e69b020f2ba493e92ad2e214388df0
michael@0: # Parent  e0d69219dd2b3b2826d186dc99c673b879409ea6
michael@0: Bug 792903. Prevent num_stops from being set to zero. r=bas
michael@0: 
michael@0: diff --git a/gfx/cairo/cairo/src/cairo-d2d-surface.cpp b/gfx/cairo/cairo/src/cairo-d2d-surface.cpp
michael@0: --- a/gfx/cairo/cairo/src/cairo-d2d-surface.cpp
michael@0: +++ b/gfx/cairo/cairo/src/cairo-d2d-surface.cpp
michael@0: @@ -1641,17 +1641,20 @@ static RefPtr<ID2D1Brush>
michael@0:  	min_dist = MIN(_cairo_d2d_dot_product(u, _cairo_d2d_subtract_point(top_left, p1)),
michael@0:  		       _cairo_d2d_dot_product(u, _cairo_d2d_subtract_point(top_right, p1)));
michael@0:  	min_dist = MIN(min_dist, _cairo_d2d_dot_product(u, _cairo_d2d_subtract_point(bottom_left, p1)));
michael@0:  	min_dist = MIN(min_dist, _cairo_d2d_dot_product(u, _cairo_d2d_subtract_point(bottom_right, p1)));
michael@0:  
michael@0:  	min_dist = MAX(-min_dist, 0);
michael@0:  
michael@0:  	// Repeats after gradient start.
michael@0: -	int after_repeat = (int)ceil(max_dist / gradient_length);
michael@0: + 	// It's possible for max_dist and min_dist to both be zero, in which case
michael@0: + 	// we'll set num_stops to 0 and crash D2D. Let's just ensure after_repeat
michael@0: + 	// is at least 1.
michael@0: + 	int after_repeat = MAX((int)ceil(max_dist / gradient_length), 1);
michael@0:  	int before_repeat = (int)ceil(min_dist / gradient_length);
michael@0:  	num_stops *= (after_repeat + before_repeat);
michael@0:  
michael@0:  	p2.x = p1.x + u.x * after_repeat * gradient_length;
michael@0:  	p2.y = p1.y + u.y * after_repeat * gradient_length;
michael@0:  	p1.x = p1.x - u.x * before_repeat * gradient_length;
michael@0:  	p1.y = p1.y - u.y * before_repeat * gradient_length;
michael@0: