762840 - Canvas: clipping regions + shadow blur cause wrong clipping offset

Status: RESOLVED WORKSFORME

(Core :: Graphics: Canvas2D, defect)

Description

[unfathomablefayl]

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20100101 Firefox/12.0
Build ID: 20120420145725

Steps to reproduce:

When creating quite complex canvas application, I stumbled upon a bug in Firefox that works correctly in other browsers (tested current opera, chrome canary and IE9).

As written in summary, reproducing this bug requires creating clipping region (that does not have to actually clip anything -- it can be big enough to contain the whole canvas) and setting context's shadowBlur to non zero value.

I created jsfiddle example that reproduces the problem: http://jsfiddle.net/JNM2m/6/


Actual results:

Image that is drawn on the canvas with such settings is partially clipped from the top (the size that is cut off depends on image's y position)


Expected results:

Both images in given jsfiddle example should look the same, except the left one should have 1px glow around edges.

Comment 1

[unfathomablefayl]

Well, it appears it works fine in Firefox 13.

I am not sure what status should be set for that case, so I'll leave it as is.