about:blank, the script with alert function - after the restart, the browser hangs

[janekptacijarabaci]

Firefox 39.0 - Nightly 42.0a1 (2015-07-31)
GM 3.3

This user script (@run-at document-end/document-start):

// ==UserScript==
// @name        Greasemonkey - issue - 2229
// @include     about:blank
// @run-at      document-end
// @grant       none
// ==/UserScript==

alert("hello"); // modal window

...after restart of the browser - e.g. after installing a new extension, e.g. using drag and drop (if the page loaded is the "about:blank" and enabled browser history), the browser hangs and has to be killed in the Task Manager (and the script must be manually disabled)!

Refs #2041 (comment), #2041 (comment), #2041 (comment)

[arantius]

Confirmed, with error:

JavaScript error: resource://gre/components/nsPrompter.js, line 357: NS_ERROR_NOT_AVAILABLE: Cannot call openModalWindow on a hidden window

Somehow we're catching the (content) window loading while the (chrome) window is still invisible, in the session restore path?

[arantius]

I found where this error is thrown but if I try to detect this case (invisible window) the same way, it causes Firefox to crash (!).

[arantius]

https://bugzilla.mozilla.org/show_bug.cgi?id=1196270

[janekptacijarabaci]

RESOLVED WORKSFORME, REOPENED...
https://bugzilla.mozilla.org/show_bug.cgi?id=1196270#c5
https://bugzilla.mozilla.org/show_bug.cgi?id=1196270#c6

[janekptacijarabaci]

@arantius
IMHO: This bug (also 1196270 - thank you in advance) is fixed for me.
See also https://bugzilla.mozilla.org/show_bug.cgi?id=1196270#c7

Last bad: 50.0a1 (2016-07-25)
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0
Built from https://hg.mozilla.org/mozilla-central/rev/7c669d5d63efceb12696cd65cfa72c296013dafb

First good: 50.0a1 (2016-07-26)
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0
Built from https://hg.mozilla.org/mozilla-central/rev/ff1ef8ec0fd800bf6856c1572c3b1610c45e9b6a

Pushlog
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=7c669d5d63efceb12696cd65cfa72c296013dafb&tochange=ff1ef8ec0fd800bf6856c1572c3b1610c45e9b6a

The suspects are: 1251841, 1261842 and 1278985.

[klenium]

I reinstalled my win10 and all programs yesterday.
Firefox 54.0.1
Greasemonkey 3.11beta1
The script above still/again blocks FF.

[janekptacijarabaci]

Confirmed.
See also https://bugzilla.mozilla.org/show_bug.cgi?id=1357383#c1
AFAIK: then it can be fixed (as described: https://bugzilla.mozilla.org/show_bug.cgi?id=1196270#c0).