e10s: crash (failure to start) when attempting to refresh with an incompatible extension enabled

[grahamperrin]

Steps

1. install e.g. Mozilla Archive Format
2. ignore the invitation to restart (try to avoid e10s: crash (failure to restart) after installing an incompatible extension #616)
3. quit
4. start
5. if there's a crash (e10s: crash (failure to restart) after installing an incompatible extension #616) then again, start
6. about:support
7. Refresh Waterfox …

Expected

• at the tail of the refresh routine, a start

Actual result

• crash.

Suggestion

Situations such as this may be avoided by ceasing to make multiprocess windows 'Enabled by user' when truly, the user has not performed that action.

The logical, less risky, more refreshing default will be:

• e10s disabled
• plus a 'power user' option to override that default.

Environment

Waterfox 56.2.0 on Kubuntu.

Crashes first observed with 56.2.0.31_5 on FreeBSD-CURRENT.

Related

Waterfox: e10s, multi-process, extensions.e10sBlocksEnabling and extensions.e10sMultiBlocksEnabling · Issue #397 …

Meta, tracking: #538

[grahamperrin]

• e10s disabled
• plus a 'power user' option to override that default.

To clarify:

• that's for where there is an incompatible extension enabled.

If Waterfox can regain the logic that it seemed to lose around the time of the update from 56.0.2 to 56.0.3 – revert or build upon 6e34597, maybe? – then an option to override (to take the risk) might be as simple as:

• a GUI to toggle extensions.e10sBlocksEnabling

– the user to proceed at his or her own risk if it's made false by the user.

I say might because I see extensions.e10sBlocksEnabling absent from Firefox 60.0.2.

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Postscript: for reference, 9c4cc55 tagged 56.0.2 was Don't block e10s if add-ons aren't compatible - let the user choose.