Bug: Windows debug artefact build: Assertion failure: !mMutationGuard.Mutated(0) (Don't mutate the DOM while using a ShadowIncludingTreeIterator), at /builds/worker/workspace/obj-build/dist/include/mozilla/dom/ShadowIncludingTreeIterator.h:39
Status: NEW
Priority: --
Created: 2023-02-02 07:40:02+00:00
Resolved: 2023-05-27 00:49:27+00:00

When I click on a message, Thunderbird debug builds crash. Most of the time it happens with the first message already, but sometimes it needs a view more clicks.

Observed on Windows.

```
[Parent 14096, Main Thread] WARNING: NS_ENSURE_TRUE(messenger) failed: file /builds/worker/checkouts/gecko/comm/mailnews/base/src/nsMsgDBView.cpp:1068
[Parent 14096, Main Thread] WARNING: '!ClientIsValidPrincipalInfo(mClientInfo.PrincipalInfo())', file /builds/worker/checkouts/gecko/dom/clients/manager/ClientSource.cpp:183
[Parent 14096, Main Thread] WARNING: Failed to retarget HTML data delivery to the parser thread.: file /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParser.cpp:1234
Assertion failure: !mMutationGuard.Mutated(0) (Don't mutate the DOM while using a ShadowIncludingTreeIterator), at /builds/worker/workspace/obj-build/dist/include/mozilla/dom/ShadowIncludingTreeIterator.h:39
#01: VR_RuntimePath[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x1a97531]
#02: DumpCompleteHeap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x12b3274]
#03: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x740bffe]
#04: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x7423f82]
#05: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x74237c6]
#06: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x740f4bd]
#07: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x742e77c]
#08: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x7428488]
#09: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x743d556]
#10: DumpCompleteHeap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x117106e]
#11: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0xb3d944]
#12: DumpCompleteHeap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x117106e]
#13: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x717864a]
#14: XRE_GetBootstrap[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x73ca1cd]
#15: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x5f511d]
#16: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x5f40ef]
#17: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x35e11a]
#18: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x38a097]
#19: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x3e4288]
#20: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x3daf82]
#21: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x3d93eb]
#22: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x3d977a]
#23: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x3e6747]
#24: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x3fd43f]
#25: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x404195]
#26: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0xe8eaf9]
#27: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0xe13940]
#28: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0xe137ff]
#29: soundtouch::SoundTouch::operator=[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x4d4ef88]
#30: soundtouch::SoundTouch::operator=[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x4e2116c]
#31: workerlz4_maxCompressedSize[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x6e6ff88]
#32: workerlz4_maxCompressedSize[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x6fe21bc]
#33: workerlz4_maxCompressedSize[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x6fe39ff]
#34: workerlz4_maxCompressedSize[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\xul.dll +0x6fe4218]
#35: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\thunderbird.exe +0x18f6]
#36: Ordinal0[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\thunderbird.exe +0x129d]
#37: TargetNtUnmapViewOfSection[F:\mozilla\mozilla-central\obj-x86_64-pc-mingw32-debug\dist\bin\thunderbird.exe +0x7e438]
#38: BaseThreadInitThunk[C:\WINDOWS\System32\KERNEL32.DLL +0x17614]
#39: RtlUserThreadStart[C:\WINDOWS\SYSTEM32\ntdll.dll +0x526a1]
```