Userscript crashes Firefox 51 in GM_registerMenuCommand

[Orivej Desh]

After updating Firefox, it started to crash occasionally with:

Assertion failure: js::GetObjectCompartment(obj) != js::GetContextCompartment(cx) (This should be invoked after entering the compartment but before wrapping the values), at /home/uj/coding/projects/firefox/firefox-51.0.1/js/xpconnect/src/ExportHelpers.cpp:296

when a userscript calls GM_registerMenuCommand.

Here is the userscript [1], its dependency that crashes Firefox [2], JS stack [3] and C stack [4].

I do not need this userscript, but the crash may indicate a bug in Firefox or GreaseMonkey. I am not sure how to make the crash reproducible.

[1] https://gist.github.com/orivej/26db287fcce35ae698af82a88e17f76d#file-95205-user-js
[2] https://gist.github.com/orivej/26db287fcce35ae698af82a88e17f76d#file-anotherautoupdater-php-L62
[3] https://gist.github.com/orivej/26db287fcce35ae698af82a88e17f76d#file-js_stack-txt
[4] https://gist.github.com/orivej/26db287fcce35ae698af82a88e17f76d#file-gdb_stack-txt