Re: [PATCH 2/2] mingw: ensure temporary file handles are not inherited by child processes

> When the index is locked and child processes inherit the handle to
> said lock and the parent process wants to remove the lock before the
> child process exits, on Windows there is a problem: it won't work
> because files cannot be deleted if a process holds a handle on them.
> The symptom:
>
>     Rename from 'xxx/.git/index.lock' to 'xxx/.git/index' failed.
>     Should I try again? (y/n)
>
> Spawning child processes with bInheritHandles==FALSE would not work
> because no file handles would be inherited, not even the hStdXxx
> handles in STARTUPINFO (stdin/stdout/stderr).
>
> Opening every file with O_NOINHERIT does not work, either, as e.g.
> git-upload-pack expects inherited file handles.
>
> This leaves us with the only way out: creating temp files with the
> O_NOINHERIT flag. This flag is Windows-specific, however. For our
> purposes, it is equivalent our purposes) to O_CLOEXEC (which does not

> exist on Windows), so let's just open temporary files with the
> O_CLOEXEC flag and map that flag to O_NOINHERIT on Windows.
>
> This fixes the test that we just introduced to demonstrate the problem.
>
> Signed-off-by: Ben Wijen <ben@wijen.net>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>