Bug 23990 – Regression (r40837): JavaScript image popup doesn't work

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Alexander Kahn]

Hi,

On this page: http://www.tetongravity.com/forums/showthread.php?t=137052&page=196 , in post #4877, clicking on one of the attached images is supposed to popup a larger version of the image. In the current nightly (41018?), it doesn't. 

However, when viewing the post on its own (http://www.tetongravity.com/forums/showpost.php?p=2260986&postcount=4877), the image pops up correctly.

Thanks to cpst for helping me file this.

[Cameron Zwarich (cpst)]

Using nightlies I tracked down this regression to the range r40813-r40884. I'll try bisecting some more with SVN.

[Cameron Zwarich (cpst)]

This regressed in r40837:

http://trac.webkit.org/changeset/40837

I'm not sure what caused the change.

[Cameron Zwarich (cpst)]

The YAHOO.util.Dom.setXY YUI function seems to be broken after r40837, but I am not sure why.

[Cameron Zwarich (cpst)]

The problem seems to be with the getXY YUI function, which sniffs getBoundingClientRect and uses it if it exists. In the case of the element in question, getBoundingClientRect().top differs from offsetTop.

[Cameron Zwarich (cpst)]

The problem is that getBoundingClientRect on all other browsers gives a negative top value if the page has been scrolled downwards. We need to emulate this behaviour (and other quirks of getBoundingClientRect) for compatibility.

I'll try to make a simple test case from this example.

[Cameron Zwarich (cpst)]

Created attachment 27764 [details]
Reduced test case

Here's a reduced test case. Clicking anywhere gives an alert with the top of the enclosing div's current bounding rectangle. Note that this is reported relative to the viewport in all other browsers.

[Cameron Zwarich (cpst)]

I'm unassigning this, because I'm probably not the one to fix it.

[Kevin M. Dean]

You mentioned scrolling the page downwards. I think I'm seeing what may be other related issues with scrolling between builds r40813 and r40884, so it could be the same bug.

I'm seeing that javascript opened content is only positioned correctly before you start scrolling. Once scrolled it opens in it's original position on the screen but not correct relative to the page content anymore.

Example: http://www.mania.com/aodvb/

On this and other forum sites, click the search or quick links drop down menus and they'll appear fine. Scroll down the page a little and then they appear out of proper position.

I'm also seeing something similar on Yahoo Personals in the photo gallery grid mode where an info box appears relative to a picture, but isn't in the right spot after scrolling.

[Cameron Zwarich (cpst)]

It's probably the same bug. The fix is to just use viewport-relative coordinates. If Sam doesn't fix it soon, I'll ask Hyatt how to fix it and do it myself.

[Sam Weinig]

Created attachment 27948 [details]
patch

[Dave Hyatt]

Comment on attachment 27948 [details]
patch

r=me

[Sam Weinig]

Fixed in r41207.

[Cameron Zwarich (cpst)]

*** Bug 24134 has been marked as a duplicate of this bug. ***