1598656 - Crash in [@ mozilla::intl::OSPreferences::ReadSystemLocales]

Status: RESOLVED FIXED

(Core :: Internationalization, defect)

Description

[Marcia Knous [:marcia]]

This bug is for crash report bp-6b8e2fca-8b5d-4acb-8a4e-404760191122.

Windows only crash which started in 20191122091512: https://bit.ly/35nM7lk. Possible regression range based on Build ID: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=76e20a306bc262843ec06d59c54416131af030cb&tochange=80ab213de5a9647fb7da0ed969a3c5a0d5ce4cdf

Maybe zbraniecki knows something since there is code in the stack from Bug 1414186.

Top 10 frames of crashing thread:

0 xul.dll mozilla::intl::OSPreferences::ReadSystemLocales intl/locale/windows/OSPreferences_win.cpp:74
1 xul.dll mozilla::intl::OSPreferences::GetSystemLocales intl/locale/OSPreferences.cpp:256
2 xul.dll void gfxPlatformFontList::AppendCJKPrefLangs gfx/thebes/gfxPlatformFontList.cpp:1694
3 xul.dll void gfxPlatformFontList::GetLangPrefs gfx/thebes/gfxPlatformFontList.cpp:1618
4 xul.dll class gfxFont* gfxFontGroup::WhichPrefFontSupportsChar gfx/thebes/gfxTextRun.cpp:3299
5 xul.dll gfxFontGroup::FindFontForChar gfx/thebes/gfxTextRun.cpp:2991
6 xul.dll static void gfxFontGroup::InitScriptRun<char16_t> gfx/thebes/gfxTextRun.cpp:2491
7 xul.dll static void gfxFontGroup::InitTextRun<char16_t> gfx/thebes/gfxTextRun.cpp:2413
8 xul.dll gfxFontGroup::MakeTextRun gfx/thebes/gfxTextRun.cpp:2285
9 xul.dll void BuildTextRunsScanner::FlushFrames layout/generic/nsTextFrame.cpp:1645

Comment 1

[Zibi Braniecki [:zbraniecki][:gandalf]]

Jonathan, is it possibly related to your yesterday's landing of bug 1593414?

If I do my math right, in the ifndef scenario this would be line 136 - https://hg.mozilla.org/mozilla-central/file/tip/intl/locale/windows/OSPreferences_win.cpp#l136

Comment 2

[Jonathan Kew [:jfkthame]]

(In reply to Zibi Braniecki [:zbraniecki][:gandalf] from comment #1)

Jonathan, is it possibly related to your yesterday's landing of bug 1593414?

Presumably so.

If I do my math right, in the ifndef scenario this would be line 136 - https://hg.mozilla.org/mozilla-central/file/tip/intl/locale/windows/OSPreferences_win.cpp#l136

I don't believe there should be any mismatch of line numbering going on.... when it says line 74, it means line 74. (AFAIK) Which makes it look like this may be happening when something goes out of scope, but it's not obvious to me what's wrong.

Comment 3

[Jonathan Kew [:jfkthame]]

I only see 12 crash reports so far (recent ones, that is - there are older Win7 crashes that look unrelated), so it's a bit early to say, but one thing I notice is that they're all from the same Windows build (10.0.18362). If that persists as more reports come in, I might begin to suspect an underlying Windows bug in that particular version.

Comment 4

[Jonathan Kew [:jfkthame]]

Ah, ok ..... checking crash-stats again, I see a few more reports are in, including one from 10.0.19013 and one from 10.0.18363.

Comment 5

[Julien Cristau [:jcristau]]

This is the #2 content crasher in the last few days in nightly.

Comment 6

[Jonathan Kew [:jfkthame]]

Although I don't currently understand why it would be causing this, I think we should back out bug 1593414 for now. Unless :emk or anyone has a better idea?

Comment 7

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1598656 - Backed out changeset af71a7b69a5e (bug 1593414) for crashiness on Nightly. r=emk

Comment 8

[Masatoshi Kimura [:emk]]

I wrote a speculation in Phabricator. globalizationPrefs->Release() and languages->Release() will be implicitly called at line 74. Sorry I could not catch this earlier.

Comment 9

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1598656 - Ensure RoUninitialize is not called until after the COMPtr<>s have been released. r=emk

Comment 10

[Jonathan Kew [:jfkthame]]

That's a good suggestion, might well explain the crashes. So I think we should try fixing that; if the crashes still persist after that, we might have to back out, but let's hope it resolves the issue.

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b9e66763153c
Ensure RoUninitialize is not called until after the COMPtr<>s have been released. r=emk

Comment 12

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/b9e66763153c

Comment 13

[Firefox Bug Husbandry Bot]

Please specify a root cause for this bug. See :tmaity for more information.