User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; pl; rv:1.9b5) Gecko/2008032620 Firefox/3.0b5 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; pl; rv:1.9b5) Gecko/2008032620 Firefox/3.0b5 When I leave a site that includes a flash object, and then return to the site through back/forward buttons on toolbar, all flash objects on the website dissapear - it looks as if there were no such objects on the page. The flash objects appear again when one hit Reload button or enter the site again by typing url. Reproducible: Always Steps to Reproduce: 1.enter the site that includes flash object(s) 2.leave the site 3.return to the site by clicking back/forward button or [Backspace]. Actual Results: If the site contained flash objects, they were not rendered at all. Expected Results: If the site contained flash objects, they should be rendered.

Confirmed with latest trunk on Windows XP. I've seen this too and I also noticed that sometimes if you don't expect it anymore the film starts to play suddenly. Regression window is http://bonsai.mozilla.org/cvsquery.cgi?module=PhoenixTinderbox&date=explicit&mindate=1206461580&maxdate=1206467519 so it seems to be caused by Bug 420886.

(In reply to comment #1) > if you don't expect it anymore the film starts to play > suddenly. > Only rarely.

+'ing as it appears to be a regression from the flash + modal dialog blocker. Mats?

This can even lead to a crash if JavaScript on the page tries to access the plug-in. See Bug 426942, which was marked as duplicate of this bug.

I can reproduce this bug, and the crash in bug 426942. I have something that appears to fix both problems...

This limits the delay path from StopPlugin() to the Real-plugin only, other plugins are not delayed - as before bug 420886. The delay is only needed for the additional STR in bug 420886 comment 15. Test builds are available here: https://build.mozilla.org/tryserver-builds/2008-04-04_19:47-mpalmgren@mozilla.com-426852_patch1/

(In reply to comment #7) > Test builds are available here: > https://build.mozilla.org/tryserver-builds/2008-04-04_19:47-mpalmgren@mozilla.com-426852_patch1/ > I used it for some hours and it solves the problem (Windows XP).

(In reply to comment #8) I meant the Back problem.

Tested patch build with XStandard plug-in on Vista and OS X 10.4.6 - it appears that the patch fixed the problem. Thank you!

This is ready to land...

Checking in layout/generic/nsObjectFrame.cpp; /cvsroot/mozilla/layout/generic/nsObjectFrame.cpp,v <-- nsObjectFrame.cpp new revision: 1.649; previous revision: 1.648 done

verified fixed using Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9pre) Gecko/2008050614 Minefield/3.0pre and the steps to reproduce