From: "Karsten Blees via GitGitGadget" <gitgitgadget@gmail•com>
To: git@vger•kernel.org
Cc: Ben Knoble <ben.knoble@gmail•com>, Johannes Sixt <j6t@kdbg•org>,
Karsten Blees <karsten.blees@gmail•com>,
Johannes Schindelin <johannes.schindelin@gmx•de>,
Karsten Blees <karsten.blees@gmail•com>
Subject: [PATCH v2 01/18] mingw: don't call `GetFileAttributes()` twice in `mingw_lstat()`
Date: Fri, 09 Jan 2026 20:04:58 +0000 [thread overview]
Message-ID: <6ec4ff74577f3690a11160812666e5ca800d9d65.1767989115.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.2018.v2.git.1767989115.gitgitgadget@gmail.com>
From: Karsten Blees <karsten.blees@gmail•com>
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>
---
compat/mingw.c | 53 ++++++++++++++------------------------------------
1 file changed, 15 insertions(+), 38 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c
index cf4f3c92e7..ae6826948e 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -918,8 +918,9 @@ static int has_valid_directory_prefix(wchar_t *wfilename)
}
/* We keep the do_lstat code in a separate function to avoid recursion.
- * When a path ends with a slash, the stat will fail with ENOENT. In
- * this case, we strip the trailing slashes and stat again.
+ * When a path ends with a slash, the call to `GetFileAttributedExW()`
+ * would fail. To prevent this, we strip any trailing slashes before that
+ * call.
*
* If follow is true then act like stat() and report on the link
* target. Otherwise report on the link itself.
@@ -928,9 +929,18 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf)
{
WIN32_FILE_ATTRIBUTE_DATA fdata;
wchar_t wfilename[MAX_PATH];
- if (xutftowcs_path(wfilename, file_name) < 0)
+ int wlen = xutftowcs_path(wfilename, file_name);
+ if (wlen < 0)
return -1;
+ /* strip trailing '/', or GetFileAttributes will fail */
+ while (wlen && is_dir_sep(wfilename[wlen - 1]))
+ wfilename[--wlen] = 0;
+ if (!wlen) {
+ errno = ENOENT;
+ return -1;
+ }
+
if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) {
buf->st_ino = 0;
buf->st_gid = 0;
@@ -990,39 +1000,6 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf)
return -1;
}
-/* We provide our own lstat/fstat functions, since the provided
- * lstat/fstat functions are so slow. These stat functions are
- * tailored for Git's usage (read: fast), and are not meant to be
- * complete. Note that Git stat()s are redirected to mingw_lstat()
- * too, since Windows doesn't really handle symlinks that well.
- */
-static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
-{
- size_t namelen;
- char alt_name[PATH_MAX];
-
- if (!do_lstat(follow, file_name, buf))
- return 0;
-
- /* if file_name ended in a '/', Windows returned ENOENT;
- * try again without trailing slashes
- */
- if (errno != ENOENT)
- return -1;
-
- namelen = strlen(file_name);
- if (namelen && file_name[namelen-1] != '/')
- return -1;
- while (namelen && file_name[namelen-1] == '/')
- --namelen;
- if (!namelen || namelen >= PATH_MAX)
- return -1;
-
- memcpy(alt_name, file_name, namelen);
- alt_name[namelen] = 0;
- return do_lstat(follow, alt_name, buf);
-}
-
static int get_file_info_by_handle(HANDLE hnd, struct stat *buf)
{
BY_HANDLE_FILE_INFORMATION fdata;
@@ -1048,11 +1025,11 @@ static int get_file_info_by_handle(HANDLE hnd, struct stat *buf)
int mingw_lstat(const char *file_name, struct stat *buf)
{
- return do_stat_internal(0, file_name, buf);
+ return do_lstat(0, file_name, buf);
}
int mingw_stat(const char *file_name, struct stat *buf)
{
- return do_stat_internal(1, file_name, buf);
+ return do_lstat(1, file_name, buf);
}
int mingw_fstat(int fd, struct stat *buf)
--
gitgitgadget
next prev parent reply other threads:[~2026-01-09 20:05 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-17 14:08 [PATCH 00/18] Support symbolic links on Windows Johannes Schindelin via GitGitGadget
2025-12-17 14:08 ` [PATCH 01/18] mingw: don't call `GetFileAttributes()` twice in `mingw_lstat()` Karsten Blees via GitGitGadget
2025-12-18 10:34 ` Johannes Sixt
2025-12-17 14:08 ` [PATCH 02/18] mingw: implement `stat()` with symlink support Karsten Blees via GitGitGadget
2025-12-18 10:44 ` Johannes Sixt
2026-01-09 20:04 ` Johannes Schindelin
2025-12-17 14:08 ` [PATCH 03/18] mingw: drop the separate `do_lstat()` function Karsten Blees via GitGitGadget
2025-12-18 10:48 ` Johannes Sixt
2025-12-17 14:08 ` [PATCH 04/18] mingw: let `mingw_lstat()` error early upon problems with reparse points Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 05/18] mingw: teach dirent about symlinks Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 06/18] mingw: compute the correct size for symlinks in `mingw_lstat()` Bill Zissimopoulos via GitGitGadget
2025-12-17 14:08 ` [PATCH 07/18] mingw: factor out the retry logic Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 08/18] mingw: change default of `core.symlinks` to false Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 09/18] mingw: add symlink-specific error codes Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 10/18] mingw: handle symlinks to directories in `mingw_unlink()` Karsten Blees via GitGitGadget
2025-12-18 2:49 ` Ben Knoble
2026-01-09 20:04 ` Johannes Schindelin
2025-12-17 14:08 ` [PATCH 11/18] mingw: support renaming symlinks Karsten Blees via GitGitGadget
2025-12-18 17:44 ` Johannes Sixt
2026-01-09 20:04 ` Johannes Schindelin
2025-12-17 14:08 ` [PATCH 12/18] mingw: allow `mingw_chdir()` to change to symlink-resolved directories Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 13/18] mingw: implement `readlink()` Karsten Blees via GitGitGadget
2025-12-18 18:13 ` Johannes Sixt
2026-01-09 20:04 ` Johannes Schindelin
2025-12-17 14:08 ` [PATCH 14/18] mingw: implement basic `symlink()` functionality (file symlinks only) Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 15/18] mingw: add support for symlinks to directories Karsten Blees via GitGitGadget
2025-12-17 14:08 ` [PATCH 16/18] mingw: try to create symlinks without elevated permissions Johannes Schindelin via GitGitGadget
2025-12-17 14:08 ` [PATCH 17/18] mingw: emulate `stat()` a little more faithfully Johannes Schindelin via GitGitGadget
2025-12-17 14:08 ` [PATCH 18/18] mingw: special-case index entries for symlinks with buggy size Johannes Schindelin via GitGitGadget
2025-12-18 0:00 ` [PATCH 00/18] Support symbolic links on Windows Junio C Hamano
2025-12-18 18:51 ` Johannes Sixt
2025-12-18 19:33 ` Karsten Blees
2026-01-09 20:04 ` [PATCH v2 " Johannes Schindelin via GitGitGadget
2026-01-09 20:04 ` Karsten Blees via GitGitGadget [this message]
2026-01-09 20:04 ` [PATCH v2 02/18] mingw: implement `stat()` with symlink support Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 03/18] mingw: drop the separate `do_lstat()` function Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 04/18] mingw: let `mingw_lstat()` error early upon problems with reparse points Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 05/18] mingw: teach dirent about symlinks Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 06/18] mingw: compute the correct size for symlinks in `mingw_lstat()` Bill Zissimopoulos via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 07/18] mingw: factor out the retry logic Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 08/18] mingw: change default of `core.symlinks` to false Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 09/18] mingw: add symlink-specific error codes Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 10/18] mingw: handle symlinks to directories in `mingw_unlink()` Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 11/18] mingw: support renaming symlinks Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 12/18] mingw: allow `mingw_chdir()` to change to symlink-resolved directories Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 13/18] mingw: implement `readlink()` Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 14/18] mingw: implement basic `symlink()` functionality (file symlinks only) Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 15/18] mingw: add support for symlinks to directories Karsten Blees via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 16/18] mingw: try to create symlinks without elevated permissions Johannes Schindelin via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 17/18] mingw: emulate `stat()` a little more faithfully Johannes Schindelin via GitGitGadget
2026-01-09 20:05 ` [PATCH v2 18/18] mingw: special-case index entries for symlinks with buggy size Johannes Schindelin via GitGitGadget
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