"Tao Klerks via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> From: Tao Klerks <tao@xxxxxxxxxx>
>
> The mingw_utime implementation in mingw.c does not support
> directories. This means that "test-tool chmtime" fails on Windows when
> targeting directories. This has previously been noted and sidestepped
> by Jeff Hostetler, in "t/helper/test-chmtime: skip directories
> on Windows" in the "Builtin FSMonitor Part 2" work.
I was expecting that this will be applicable _before_ FSMonitor Part
2 and later. This mention would probably belong to the comment
after three-dashes?
> It would make sense to backdate file and folder changes in untracked
> cache tests, to avoid needing to insert explicit delays/pauses in the
> tests.
>
> Add support for directory date manipulation in mingw_utime by calling
> CreateFileW() explicitly to create the directory handle, and
> CloseHandle() to close it.
OK.
> @@ -964,6 +964,8 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
> int fh, rc;
> DWORD attrs;
> wchar_t wfilename[MAX_PATH];
> + HANDLE osfilehandle;
The variable is not initialized here, but that is perfectly OK.
We'll set it in both branches for directories and files.
> if (xutftowcs_path(wfilename, file_name) < 0)
> return -1;
>
> @@ -975,9 +977,26 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
> SetFileAttributesW(wfilename, attrs & ~FILE_ATTRIBUTE_READONLY);
> }
>
> - if ((fh = _wopen(wfilename, O_RDWR | O_BINARY)) < 0) {
> - rc = -1;
> - goto revert_attrs;
> + if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
Excellent. We can reuse existing attrs without any extra calls to
introduce the new codepath to deal with directories.
> + fh = 0;
This should be
fh = -1;
instead. More on this later.
> + osfilehandle = CreateFileW(wfilename,
> + 0x100 /*FILE_WRITE_ATTRIBUTES*/,
> + 0 /*FileShare.None*/,
> + NULL,
> + OPEN_EXISTING,
> + FILE_FLAG_BACKUP_SEMANTICS,
> + NULL);
> + if (osfilehandle == INVALID_HANDLE_VALUE) {
> + errno = err_win_to_posix(GetLastError());
> + rc = -1;
> + goto revert_attrs;
> + }
Upon an error, we'll jump to revert_attrs but otherwise, we will
have a valid osfilehandle (which presumably is not NULL).
> + } else {
> + if ((fh = _wopen(wfilename, O_RDWR | O_BINARY)) < 0) {
> + rc = -1;
> + goto revert_attrs;
> + }
> + osfilehandle = (HANDLE)_get_osfhandle(fh);
This side is the same as before. This code assumes that, as long as
_wopen() gives us a usable fh, _get_osfhandle(fh) would always give
us a valid handle. This assumption should be safe, as the original
code has been relying on it anyway.
> @@ -987,12 +1006,16 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
> GetSystemTimeAsFileTime(&mft);
> aft = mft;
> }
> - if (!SetFileTime((HANDLE)_get_osfhandle(fh), NULL, &aft, &mft)) {
> + if (!SetFileTime(osfilehandle, NULL, &aft, &mft)) {
And we use the osfilehandle we obtained, either from the code that
is identical to the original for files or from the new code for
directories. Good.
> errno = EINVAL;
> rc = -1;
> } else
> rc = 0;
> - close(fh);
> +
> + if (fh)
> + close(fh);
> + else if (osfilehandle)
> + CloseHandle(osfilehandle);
In the context of "git" process, I do not think we would ever close
FD#0, so it may be safe to assume that _wopen() above will never
yield FD#0, so this is not quite wrong per-se, but to be
future-proof, it would be even safer to instead do:
if (0 <= fh)
close(fh);
else if (osfilehandle)
CloseHandle(osfilehandle);
here. That is consistent with the error checking done where
_wopen() was called to obtain it above, i.e.
if ((fh = _wopen(...)) < 0)
... error ...
> revert_attrs:
> if (attrs != INVALID_FILE_ATTRIBUTES &&
