Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b3) Gecko/20050714 Firefox/1.0+ ID:2005071403 This bug is a regression, as discovered from www.liveforspeed.net Clicking on the graphical links causes the links to flicker like mad. This happens on the trunk (Deer Park alpha 2) but not on the branch (Firefox 1.05). I have no idea if this is a JS issue or a layout issue. But after filing this bug, I hope someone with more knowledge can chime in. Graphics and testcase attachments to follow.

Steps to reproduce 1. Load testcase 2. Hover over the graphical links. Note it does some fancy fade-in for the colours (which is actually just some trickery involving the image files and some JS) 3. Left click any of the graphical links. Actual: Usually the image you clicked on will start to flicker like mad. Expected: The link is followed; no flickering is exhibited This works fine on the branch (1.05) but not on the trunk (Deer Park alpha 2). I have no idea if this is a JS issue, or a layout issue.

After clicking a graphical link on the testcase, you might have to move your mouse left/right ever so slightly in order for the flickering to start up.

The JS uses onmouseover and onmouseout events to animate the fade-in/out. After you click the link, the object will get a stream of alternating onmouseover/onmouseout events causing the flickering as the JS rapidly toggles the fading effect. Unless I'm mistaken, this belongs in the event component - neither JS nor Layout.

On 1-1-2005 the links already flickered, but only three times.:) To get flicker-free links, you need to go back to end July 2004. Between those dates there were also strange dotted lines through the links..

There are a bunch of regression ranges here: In firefox 1.05, the links work as expected when clicked and focused (no flicker) In early 2004 builds, the links do not flicker when clicked and focused. In later 2004 builds, the links flicker for a while (1-3 seconds) and then stop. In early 2005 builds, the links flicker 3 times only when clicked and focused In most recent builds, the links flicker constantly when clicked and focused The regression range between 'no flicker' and 'flicker for a while then stop' is between 2004-07-24-09 (no flicker) and 2004-07-26-14 (flickers for a while then stops) Checkin Range http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=all&branch=HEAD&branchtype=match&dir=mozilla%2Flayout%2Fstyle+mozilla%2Flayout%2Fbase+mozilla%2Flayout%2Fgeneric+mozilla%2Feditor%2Flibeditor+mozilla%2Fcontent%2Fevents+mozilla%2Fview%2F&file=&filetype=match&who=&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2004-07-24+08%3A00&maxdate=2004-07-26+14%3A00&cvsroot=%2Fcvsroot Bug 252948? I have not bothered to find a regression between 'flicker for a while then stop' and 'flickers 3 times only' (Although if this would be useful, I can do) The regression range between 'flicker 3 times' and 'flicker constantly' is between 2005-01-19-17 and 2005-01-20-11 Checking Range http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=all&branch=HEAD&branchtype=match&dir=mozilla%2Flayout%2Fstyle+mozilla%2Flayout%2Fbase+mozilla%2Flayout%2Fgeneric+mozilla%2Feditor%2Flibeditor+mozilla%2Fcontent%2Fevents+mozilla%2Fview%2F&file=&filetype=match&who=&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2005-01-19+16%3A00&maxdate=2005-01-20+11%3A00&cvsroot=%2Fcvsroot Bug 244366 looks guilty in this case Thanks to Gavin Sharp for some regression range finding.

So in fact that first regression happened between 2004-07-24-09 and 2004-07-25-07. I'm almost certain that bug 250006 is what caused it -- notice that not only does the link start to flicker but it also ends up painted yellow instead of the white it should be. Note that you get the same issue on right-click and that tabbing through the links makes them all yellow (hence my assumption that bug 250006 is the problem). Aaron, any idea what's going on here? Martijn, do you think we could end up with a simpler testcase?

This is what I think is going on: 1- When focusing the link, Mozilla shifts the link with the image inside to the bottom in a (failing) attempt to get the focused content in view. 2- When mouseovering the image, the script says to move it 21px up, that means the image's position gets higher than the mouse position -> a mousout event is fired. 3- Then the domouseout function gets done, it tells the image to position itself 21px lower, the mouse gets again over the image -> a mouseover event is fired and step 2 is again followed, etc. So an endless loop is created this way. You can more easily see this when the containing div has overflow:visible (click on the button) and then moving the mouse from below the image into the image.

we'd consider taking a patch for this if one happens but I don't think we're going to block on a year old regression.

I think this is basically exposed by the fix for bug 20022, but it should be (partially) fixed when bug 105894 gets fixed.

fixed by bug 105894.

v.fixed on 1.8.0.1 with Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1, appears to be fixed based on testcase2 in comment #12.