mingw: allow mingw_chdir() to change to symlink-resolved directories

If symlinks are enabled, resolve all symlinks when changing directories,
as required by POSIX.

Note: Git's `real_path()` function bases its link resolution algorithm
on this property of `chdir()`. Unfortunately, the current directory on
Windows is limited to only MAX_PATH (260) characters. Therefore using
symlinks and long paths in combination may be problematic.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Karsten Blees 2025-12-17 14:08:49 +00:00 committed by Junio C Hamano
parent c4314a6aa8
commit 8a08d14d05

View File

@ -866,9 +866,27 @@ int mingw_access(const char *filename, int mode)
int mingw_chdir(const char *dirname)
{
wchar_t wdirname[MAX_PATH];
if (xutftowcs_path(wdirname, dirname) < 0)
return -1;
return _wchdir(wdirname);
if (has_symlinks) {
HANDLE hnd = CreateFileW(wdirname, 0,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
if (hnd == INVALID_HANDLE_VALUE) {
errno = err_win_to_posix(GetLastError());
return -1;
}
if (!GetFinalPathNameByHandleW(hnd, wdirname, ARRAY_SIZE(wdirname), 0)) {
errno = err_win_to_posix(GetLastError());
CloseHandle(hnd);
return -1;
}
CloseHandle(hnd);
}
return _wchdir(normalize_ntpath(wdirname));
}
int mingw_chmod(const char *filename, int mode)