GNOME Bugzilla – Bug 620469
Dead Gecko accessibles encountered by Orca result in a hang
Last modified: 2010-08-20 20:58:59 UTC
To reproduce this problem, do the following: 1. Go to the follosing page: http://www.azui.com. 2. After the initial page loads, press the down arrow key to begin reading vertically down the page a line at a time. With Firefox 3.5.9, I lose speech and the only thing I can do at that point is press Ctrl-W to exit the browser, at which point, all is fine again. The only way I can get past this point while on that page at the top is press 'o' to jump to next large object. If I use FF 3.6.5, I also lose speech as described before but when I press Ctrl-W to exit FF, Firefox crashes! I should also state here that while at the top of this same page, if I press 'l' to find the next list, both FF 3.5.9 and 3.6.5 crash.
Created attachment 162651 [details] Debug file created while pressing down arrow from top of page. This time, I was in FF 3.6.5 but the program did not crash as previously described. But after down-arrow was pressed each time, I found a bunch of messages in the debug file: Object deemed useless: [section | ]
I can confirm something very bad is taking place here. But it's not a structural navigation issue; it's something bigger/uglier than that. Still investigating what, but... Blurgh. I'll take this one. Thanks for the report Steve!
This is yet another (albeit a more severe) instance of the dead accessible Mozilla bug: https://bugzilla.mozilla.org/show_bug.cgi?id=420993 It had been a little over a year since the last time I pinged that bug, so I just pinged it again. <sighs> On previous encounters with this bug, the end result was that Orca could not be used to navigate past the dead accessible in question. In this particular case, something is causing us to loop endlessly. So my goal is to stop the loop; I may or may not be able to make this page navigable with Orca. The Mozilla guys need to fix this bug.
https://www.ncsecu.org/ suffers from this problem as well. But only in FF 3.6.x; 3.5.x is dead-accessible free when viewing this page.
Alex Surkov has patches for two issues related to these hangs. I still need to test them and see if there's anything else that needs to be done.
*** Bug 622319 has been marked as a duplicate of this bug. ***
This is actively being addressed by the Mozilla guys. (Yay!) The amount of work we would have to do in Orca to verify that each and every object was not a 'dead' accessible each and every time, and then try to figure out how to move around the dead body under various and sundry circumstances to locate a valid accessible is considerable and would likely impact performance. :-( Since the Mozilla guys are fixing it on their end anyway, I'm blocking this bug against theirs and removing this from our 3.0! list.
The good news is that the hang is gone, fixed quite recently in Gecko 2/Mozilla 4.0 beta. There still seems to be some occasional weirdness navigating around the tables in question, but my understanding is the Mozilla guys are still working on what has been dubbed "crazy tables." In addition, we still have bug 520297 for the presence of dead accessibles (which in at least one case doesn't seem to actually be fixed.) Therefore, closing this one out as NOTGNOME.