See attachment 208637 [details] in bug 323628. You can't follow the instructions in the testcase, because when you try to hover the popup for the submenu, it disappears.

That testcase doesn't describe a valid menu (there is a menuitem directly inside a menu), so its expected behaviour is undefined at this point. Regardless, the popup doesn't disappear for me at least on Mac. The crash of bug 323628 is fixed though.

The same thing happens (the popup can't be hovered) with the CSS rule with the normal menu. I'm on Windows. <?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin/config.css" type="text/css"?> <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" xmlns:html="http://www.w3.org/1999/xhtml" title="Testcase bug 323628 - Crash [@ PresShell::HandleDOMEventWithTarget] when closing submenu of popup with ::after css rule" > <html:style> menu:after { content: "text"; } </html:style> <button type="menu" label="Click on the button to get the popup"> <menupopup> <menuitem label="Clicking on this should not crash Mozilla"/> <menu label="Hover over this"> <menupopup> <menuitem label="Clicking on this should not crash Mozilla"/> </menupopup> </menu> </menupopup> </button> </window>

Nickolay, I don't see any issue with this last case either. Do you have a testcase that shows this?

Well, with a build pulled Jul 15 03:42:47 GMT+4 2007, if I open the testcase from comment 2 in the live XUL editor (builds a data: URI and opens it as a chrome window, shouldn't matter), when I click the button and hover (using the mouse) the "Hover over this" menu item (the one at the bottom), a menupopup appears, saying 'Clicking on this should not crash Mozilla'. However when I hover that popup to try and click the menu item, it disappears. Again, this is windows. I should probably check if others can reproduce this. BTW: if I dismiss and re-open the first popup, the "Hover over this" menu item is pre-selected, which doesn't usually happen with menu popups.