893330 - Funny thing happens when a single div uses both box-shadow and border-radius, and change positions

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Attachment: Testcase

Sorry for the non-descriptive summary, but you will get the idea when trying out the test case . I suspect this is a dup too coz it's very easy to reproduce.

Expected result:
a div rendered as a circle moved by setInterval()

Actual result:
the div itself doesn't seems to be updated, and the shadow and border of the previous position remains.

Real world example:
http://timdream.org/wordcloud2.js/#web-tech and hover the mouse over the canvas.

Comment 1

[Nick Cameron [:nrc]]

I would put a small amount of money on this being a mask layers bug. We should add a pref for mask layers so this is easy to test. Does using a box-shadow do something interesting to the layers?

Comment 2

[Nick Cameron [:nrc]]

(In reply to Nick Cameron [:nrc] from comment #1)
> I would put a small amount of money on this being a mask layers bug. We
> should add a pref for mask layers so this is easy to test. Does using a
> box-shadow do something interesting to the layers?

Well, turns out it is not a mask layer bug at all. There are no mask layers created for this test case.

Comment 3

[Nick Cameron [:nrc]]

My current working theory is that we are not resetting a clip after drawing a box shadow and so we end up not overdrawing the frame.

It seems that the problem is here without border radius too, but in that case we are overdrawing just what we are drawing, so we don't see it.

Comment 4

[Nick Cameron [:nrc]]

Turns out all my theories were wrong. It is an invalidation issue (I think). Patch coming up...

Comment 5

[Nick Cameron [:nrc]]

Attachment: patch

Comment 6

[Matt Woodrow (:mattwoodrow)]

Comment on attachment 794379 [details] [diff] [review]
patch

Review of attachment 794379 [details] [diff] [review]:
-----------------------------------------------------------------

Nice

Comment 7

[Nick Cameron [:nrc]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d9f853609281

Comment 8

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Needs a test!

Comment 9

[Nick Cameron [:nrc]]

Attachment: reftest

Comment 10

[Nick Cameron [:nrc]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/9802d4d9a79a

Comment 11

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/d9f853609281
https://hg.mozilla.org/mozilla-central/rev/9802d4d9a79a