Tests: Protect RefRepos with mutex before reset

[gerhardol]

Proposed changes

Many tests (one out of four?) have failed recently:

LibGit2Sharp.LockedFileException : the index is locked; this might be due to a concurrent or crashed process

https://ci.appveyor.com/project/gitextensions/gitextensions/builds/42433206

These issues occur when a ReferenceRepository is to be reset before next test case.
There seem to be some reuse of repos, parallel tests or repos that happen to use the same path.

The reason for the failure is unknown, but the reset is just a way to speed up the test and should not fail the test case.
So a try-catch to create a new repo is used.

Two tests became unstable after this, ignoring.
I have no clue why they occur after these changes, seem to be related to .net5

   at GitExtensions.UITests.CommandsDialogs.FormEditorTests.Should_preserve_encoding(Encoding encoding) in C:\projects\gitextensions\IntegrationTests\UI.IntegrationTests\CommandsDialogs\FormEditorTests.cs:line 87
   at GitExtensions.UITests.CommandsDialogs.FormEditorTests.Should_preserve_encoding_utf8_bom() in C:\projects\gitextensions\IntegrationTests\UI.IntegrationTests\CommandsDialogs\FormEditorTests.cs:line 82
  Expected: <System.Text.UTF8Encoding>
  But was:  <System.Text.UTF8Encoding+UTF8EncodingSealed>

Edit: The initial version of this PR used a mutex to protect simultaneous changes but that did not prevent all changes.
That solution was inspired by https://github.com/GitTools/GitVersion/pull/2669/files

Test methodology

Rerun AppVeyor tests many times (manually).

Merge strategy

I agree that the maintainer squash merge this PR (if the commit message is clear).

---

✒️ I contribute this code under The Developer Certificate of Origin.

[mstv]

+1

[mstv]

Perhaps ignore +UTF8EncodingSealed?

[gerhardol]

I really would like to know why this appear at this point, also when rolling back the changes...
What exact wording do you want?

[mstv]

(Too short as too often) I meant to make the test accept both results.

[gerhardol]

I do not see a way to create this encoding.
Would a regex match on the output encoding text be OK?

[mstv]

I withdraw my proposal because I do not know enough about this topic.
BTW: For #9860, a BOM must be added to the English.xlf.
Perhaps this is caused by different .NET patch levels of different AppVeyor instances.

[gerhardol]

@RussKie Suggestions how to proceed with these tests?
(of course you are welcome to comment on the rest of the PR too...)

[RussKie]

BTW: For #9860, a BOM must be added to the English.xlf.
Perhaps this is caused by different .NET patch levels of different AppVeyor instances.

This sounds like dotnet/runtime#63585

[gerhardol]

Rebased on master as merge of #9805 required this update too.

[RussKie]

Two tests became unstable after this, ignoring. I have no clue why they occur after these changes, seem to be related to .net5

   at GitExtensions.UITests.CommandsDialogs.FormEditorTests.Should_preserve_encoding(Encoding encoding) in C:\projects\gitextensions\IntegrationTests\UI.IntegrationTests\CommandsDialogs\FormEditorTests.cs:line 87
   at GitExtensions.UITests.CommandsDialogs.FormEditorTests.Should_preserve_encoding_utf8_bom() in C:\projects\gitextensions\IntegrationTests\UI.IntegrationTests\CommandsDialogs\FormEditorTests.cs:line 82
  Expected: <System.Text.UTF8Encoding>
  But was:  <System.Text.UTF8Encoding+UTF8EncodingSealed>

Is this happening for your locally or on AppVeyor? If it's failing locally, check dotnet/runtime#43295, may be it can give you some clues.

[gerhardol]

Is this happening for your locally or on AppVeyor? If it's failing locally, check dotnet/runtime#43295, may be it can give you some clues.

Both, also when reverting. Maybe AppVeyor images differs, this is seen in #9680 too.
#9856 (comment)

[mstv]

Let's take this as it is.
The ignored tests can be re-enabled when the dotnet/runtime bugs have been fixed, keyword UTF8EncodingSealed.

[RussKie]

Have you observed utf8 related tests failing on the vs2022 image?

[gerhardol]

Have you observed utf8 related tests failing on the vs2022 image?

I have not used the vs2022 image myself

[mstv]

Have you observed utf8 related tests failing on the vs2022 image?

Yes, I did but not always, e.g. https://ci.appveyor.com/project/gitextensions/gitextensions/builds/42471108#L370.

[gerhardol]

Can this be merged, it is quite annoying that tests fail so often.

For the disabled tests, it seem to be a coincidence that this occur after this change and I can drop that commit but it seems like it will continue occurring.
We can add an issue about it (that will be closed in some months but at least a reminder...)