Firefox 55: g<Esc> = crash

[congma]

Just to report a crash.

With Firefox 55.0.2, pentadactyl sort of works. But when the key sequence gEsc is pressed, Firefox immediately crashes.

[magnetophon]

I can reproduce this, also on 55.0.2.

[wshanks]

Hmm, okay. That seems hard to debug because of the crashing. I assume you are making sure that multiprocessing is turned off.

Have you tried in a fresh profile with multiprocessing disabled? 55 was a pretty bad experience for me to start out (freezing and crashing randomly). I created a new profile and installed only WebExtensions in it and Firefox has been running smoothly that way, so I think there might have been some changes that combine badly with XUL addons.

Post here if you find any other sequences that reliably crash Firefox.

I might be able to help some with figuring out what is going on, but I think it will require carefully stepping through in the debugger to figure out where the crash is, and it's hard for me to justify spending much time on it because I am pretty busy and I'd rather spend time on something else like finding a replacement for Pentadactyl that will work after version 56.

[congma]

The crash is getting a bit ridiculous... This is another reliable crash for me: simply typing Enter in "Normal mode" (that is, not in an input field or something) will crash it.

Could anyone replicate this?

[magnetophon]

@congma yup, I can reproduce the Enter crash. :(

[jonlorusso]

Are there any workarounds for the Enter and g <Esc> behaviors?

[upsuper]

FYI, fix has landed in this bug but it is probably not very likely it would get to 55 given that it is near the end of this cycle. Maybe 56 can get it :/

[wshanks]

Wow, nice work tracking down that bug. So is there no easy way to work around the bug in Pentadactyl in 55?

[upsuper]

This crash wouldn't happen if you don't pass KeyboardEvent created from script to dispatchDOMEventViaPresShell. I don't know if it is possible to avoid for you, though.

[wshanks]

It seems like the only usage is at https://github.com/5digits/dactyl/blob/31a6ba0bcbf92bb393a529bde78610ee2297b55c/common/modules/dom.jsm#L1484 I wonder how bad it would be to take out that conditional and just do target.dispatchEvent(event) instead.

Also, noting that this issue seems to be the same as 5digits/dactyl#216

[wshanks]

Okay, well, I just did some quick testing with Firefox 56 beta and the current Pentadactyl xpi doesn't crash for me there, so I'm going to close this. I don't think it's worth putting a workaround in just for 55.