In container posix semantics

[YO4]

#59 complains that remove does not work in docker volume folder.
That seems to mounted folder does not support *_POSIX_SEMANTICS functions in hyper-v container.
https://ci.appveyor.com/project/YO4/test-msys2-in-container/builds/46432262

Since it is unclear how to determine in advance whether posix semantics will work, fall back to the conventional method when an error occurs.

Functions affected are unlink(), rename(), and their derivatives.

[jeremyd2019]

I assume this issue also exists in upstream Cygwin. It might make sense to send this patch upstream to cygwin-patches@cygwin.com and get their opinions/ideas, and hopefully get something applied there first.

[AJDurant]

Since it is unclear how to determine in advance whether posix semantics will work, fall back to the conventional method when an error occurs.

This is the thing I was stuck on, your solution seems neat to me.

[YO4]

I updated test https://ci.appveyor.com/project/YO4/test-msys2-in-container/builds/46532757
and posted patches to cygwin-patches.

[dscho]

For lurkers, the Cygwin contribution can be seen here.

[YO4]

Now this patches are merged into upstream/master, 527dd1b 7666e24 87ab6c7
And they added making a decision in advance with FILE_SUPPORTS_OPEN_BY_FILE_ID fe2545e

[dscho]

@YO4 personally, I'd love to see the changes backported early into the MSYS2 runtime (once the jury has decided on FILE_SUPPORTS_OPEN_BY_FILE_ID that is, and the patches have stabilized).

[YO4]

Hmmm, I saw https://github.com/msys2/msys2-runtime/tags and mistakenly assumed that msys2-runtime would not be updated until cygwin's next release.
If msys2-runtime can be released with a new pkgrel before the next release of cygwin, I would like to see this PR merged.
At this time, this patch does not include a decision on FILE_SUPPORTS_OPEN_BY_FILE_ID, but it is preferable to be able to complete the process with a retry rather than have it fail.

[dscho]

If msys2-runtime can be released with a new pkgrel before the next release of cygwin, I would like to see this PR merged.

I see that the upstream version is slightly different: 87ab6c7#diff-bf890865130314cb545fec4788e41d9daa5dd8832a21435c6556619d5578a8aaL740-R744 does not look like 749d3a2#diff-bf890865130314cb545fec4788e41d9daa5dd8832a21435c6556619d5578a8aaR739-R741

Other than that, I am totally in favor of merging it and incrementing the pkgrel.

[AJDurant]

@YO4 can you make the change that @dscho mentioned in #141 (comment) so this can get merged?

[AJDurant]

Suggested change

	goto out;
	debug_printf ("NtSetInformationFile (%S, FileDispositionInformationEx)"
	" returns %y with posix semantics. Disable it and retry.",
	pc.get_nt_native_path (), status);
	{
	debug_printf ("NtSetInformationFile returns %y "
	"with posix semantics. Disable it and retry.", status);
	goto out;
	}