1721695 - hangs during spell-check, 100% cpu, requires force quit

Status: RESOLVED DUPLICATE of bug 1721801

(Thunderbird :: Message Compose Window, defect)

Description

[Calum Mackay]

Attachment: Sample of Thunderbird Daily 20210721.txt

In Daily 20210720 (onwards) clicking the "Spelling" button in the Compose window causes, in some circumstances, a hang, consuming 100% and requiring a force quit.

It seems to happen when the spell-checker finds a misspelt word, and is looking for alternatives.

This is on MacOS 10.15.7

[edited] regression window:
0719 OK
0720 BAD

MacOS thread sample attached.

Comment 1

[Calum Mackay]

Note that I cannot get it to reproduce in all cases.

For example, composing a new msg, with a random spelling mistake: OK.

Replying to a message, random mistake: OK

Replying to same message, different spelling mistake: hang

Comment 2

[Calum Mackay]

Odd as this sounds, the following seems to be reproducible, for me:

reply to plain text message (thus has inline quoted message); add single line of text at top "hi Dai,", click Spelling button - hang

reply to plain text message (thus has inline quoted message); do not add any new text, click Spelling button - - does not hang, no misspelled words

reply to plain text message; delete inline quoted message, add single line of text at top "hi Dai," click Spelling button - does not hang, no misspelled words

compose new message, add single line of text at top "hi Dai," click Spelling button - does not hang, no misspelled words

Comment 3

[Calum Mackay]

i.e. it seems to be the combination of the inline quoted message, and the text I add, that results in the hang.

Either alone (same text in all cases) does not hang

Comment 4

[Calum Mackay]

added text "hi" seems sufficient, in combination with inline quoted text.

happens when replying to different messages, so the inline quoted text content seems not to be relevant, as long as there is something quoted.

Comment 5

[Calum Mackay]

narrowed regression window:

0719 OK
0720 BAD

Comment 6

[Calum Mackay]

forgot to note: I'm using the localised latest-comm-central-l10n build, en-GB.

Comment 7

[Calum Mackay]

hang still present in 20210804.