mingw: don't call `GetFileAttributes()` twice in `mingw_lstat()`
The Win32 API function `GetFileAttributes()` cannot handle paths with trailing dir separators. The current `mingw_stat()`/`mingw_lstat()` implementation calls `GetFileAttributes()` twice if the path has trailing slashes (first with the original path that was passed as function parameter, and and a second time with a path copy with trailing '/' removed). With the conversion to wide Unicode, we get the length of the path for free, and also have a (wide char) buffer that can be modified. This makes it easy to avoid that extraneous Win32 API call. Signed-off-by: Karsten Blees <karsten.blees@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Karsten Blees committed
Jan 9, 2026 at 20:04 UTC
3b96b99683679ee0d0c4e05cb5d1da37e13e02e5
1 file changed
+15
-38
compat/mingw.c
+15
-38
@@ -918,8 +918,9 @@ static int has_valid_directory_prefix(wchar_t *wfilename)
918
}
919
920
/* We keep the do_lstat code in a separate function to avoid recursion.
921
- * When a path ends with a slash, the stat will fail with ENOENT. In
922
- * this case, we strip the trailing slashes and stat again.
921
+ * When a path ends with a slash, the call to `GetFileAttributedExW()`
922
+ * would fail. To prevent this, we strip any trailing slashes before that
923
+ * call.
924
*
925
* If follow is true then act like stat() and report on the link
926
* target. Otherwise report on the link itself.
@@ -928,9 +929,18 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf)
929
{
930
WIN32_FILE_ATTRIBUTE_DATA fdata;
931
wchar_t wfilename[MAX_PATH];
931
- if (xutftowcs_path(wfilename, file_name) < 0)
932
+ int wlen = xutftowcs_path(wfilename, file_name);
933
+ if (wlen < 0)
934
return -1;
935
936
+ /* strip trailing '/', or GetFileAttributes will fail */
937
+ while (wlen && is_dir_sep(wfilename[wlen - 1]))
938
+ wfilename[--wlen] = 0;
939
+ if (!wlen) {
940
+ errno = ENOENT;
941
+ return -1;
942
+ }
943
+
944
if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) {
945
buf->st_ino = 0;
946
buf->st_gid = 0;
@@ -990,39 +1000,6 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf)
1000
return -1;
1001
}
1002
993
-/* We provide our own lstat/fstat functions, since the provided
994
- * lstat/fstat functions are so slow. These stat functions are
995
- * tailored for Git's usage (read: fast), and are not meant to be
996
- * complete. Note that Git stat()s are redirected to mingw_lstat()
997
- * too, since Windows doesn't really handle symlinks that well.
998
- */
999
-static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
1000
-{
1001
- size_t namelen;
1002
- char alt_name[PATH_MAX];
1003
-
1004
- if (!do_lstat(follow, file_name, buf))
1005
- return 0;
1006
-
1007
- /* if file_name ended in a '/', Windows returned ENOENT;
1008
- * try again without trailing slashes
1009
- */
1010
- if (errno != ENOENT)
1011
- return -1;
1012
-
1013
- namelen = strlen(file_name);
1014
- if (namelen && file_name[namelen-1] != '/')
1015
- return -1;
1016
- while (namelen && file_name[namelen-1] == '/')
1017
- --namelen;
1018
- if (!namelen || namelen >= PATH_MAX)
1019
- return -1;
1020
-
1021
- memcpy(alt_name, file_name, namelen);
1022
- alt_name[namelen] = 0;
1023
- return do_lstat(follow, alt_name, buf);
1024
-}
1025
-
1003
static int get_file_info_by_handle(HANDLE hnd, struct stat *buf)
1004
{
1005
BY_HANDLE_FILE_INFORMATION fdata;
@@ -1048,11 +1025,11 @@ static int get_file_info_by_handle(HANDLE hnd, struct stat *buf)
1025
1026
int mingw_lstat(const char *file_name, struct stat *buf)
1027
{
1051
- return do_stat_internal(0, file_name, buf);
1028
+ return do_lstat(0, file_name, buf);
1029
}
1030
int mingw_stat(const char *file_name, struct stat *buf)
1031
{
1055
- return do_stat_internal(1, file_name, buf);
1032
+ return do_lstat(1, file_name, buf);
1033
}
1034
1035
int mingw_fstat(int fd, struct stat *buf)