Starting with go1.22 the standard os.MkdirAll has improved its handling of volume names,
and as part of that it now stops recursing into parent directory if it is a volume name
(see: cd589c8a73).
This is similar to what was our main change and reason for creating a custom version. When
building with go1.22 or newer we can therefore stop using our custom version, with the
advantage that we automatically get current and future relevant improvements from golang.
To support building with go1.21 the existing custom version is still kept, and therefore
also our wrapper function file.MkdirAll - but it now just calls os.MkdirAll with go1.22
or newer on Windows.
See #5401, #6420 and acf1e2df84 for details about the
creation of our custom version of MkdirAll.
In ths security related issue the go1.21.4 stdlib changed the parsing
of volume names on Windows.
https://github.com/golang/go/issues/63713
This had the consequences of breaking the MkdirAll tests which were
looking for specific error messages which changed and using invalid
paths.
In particular under go1.21.3:
filepath.VolumeName(`\\?\C:`) == `\\?\C:`
But under go1.21.4 it is:
filepath.VolumeName(`\\?\C:`) == `\\?`
The path `\\?\C:` isn't actually a valid Windows path. I reported this
as a FYI bug upstream - I'm not expecting it to be fixed.
See: https://github.com/golang/go/issues/64101
This replaces built-in os.MkdirAll with a patched version that stops the recursion
when reaching the volume part of the path. The original version would continue recursion,
and for extended length paths end up with \\? as the top-level directory, and the error
message would then be something like:
mkdir \\?: The filename, directory name, or volume label syntax is incorrect.
