From d08f0011ae706e5dcae4523c60a2b005833fe354 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 16 Dec 2025 15:33:45 +0000 Subject: [PATCH 01/23] mingw: do resolve symlinks in `getcwd()` As pointed out in https://github.com/git-for-windows/git/issues/1676, the `git rev-parse --is-inside-work-tree` command currently fails when the current directory's path contains symbolic links. The underlying reason for this bug is that `getcwd()` is supposed to resolve symbolic links, but our `mingw_getcwd()` implementation did not. We do have all the building blocks for that, though: the `GetFinalPathByHandleW()` function will resolve symbolic links. However, we only called that function if `GetLongPathNameW()` failed, for historical reasons: the latter function was supported for a long time, but the former API function was introduced only with Windows Vista, and we used to support also Windows XP. With that support having been dropped, we are free to call the symbolic link-resolving function right away. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- compat/mingw.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index f09b49ff21ddab..cf4f3c92e7a889 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1239,18 +1239,16 @@ char *mingw_getcwd(char *pointer, int len) { wchar_t cwd[MAX_PATH], wpointer[MAX_PATH]; DWORD ret = GetCurrentDirectoryW(ARRAY_SIZE(cwd), cwd); + HANDLE hnd; if (!ret || ret >= ARRAY_SIZE(cwd)) { errno = ret ? ENAMETOOLONG : err_win_to_posix(GetLastError()); return NULL; } - ret = GetLongPathNameW(cwd, wpointer, ARRAY_SIZE(wpointer)); - if (!ret && GetLastError() == ERROR_ACCESS_DENIED) { - HANDLE hnd = CreateFileW(cwd, 0, - FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, - OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); - if (hnd == INVALID_HANDLE_VALUE) - return NULL; + hnd = CreateFileW(cwd, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + if (hnd != INVALID_HANDLE_VALUE) { ret = GetFinalPathNameByHandleW(hnd, wpointer, ARRAY_SIZE(wpointer), 0); CloseHandle(hnd); if (!ret || ret >= ARRAY_SIZE(wpointer)) @@ -1259,13 +1257,11 @@ char *mingw_getcwd(char *pointer, int len) return NULL; return pointer; } - if (!ret || ret >= ARRAY_SIZE(wpointer)) - return NULL; - if (GetFileAttributesW(wpointer) == INVALID_FILE_ATTRIBUTES) { + if (GetFileAttributesW(cwd) == INVALID_FILE_ATTRIBUTES) { errno = ENOENT; return NULL; } - if (xwcstoutf(pointer, wpointer, len) < 0) + if (xwcstoutf(pointer, cwd, len) < 0) return NULL; convert_slashes(pointer); return pointer; From 89d6c35322462c999fcaffb77c1d340b41df9a7a Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 16 Dec 2025 15:33:46 +0000 Subject: [PATCH 02/23] init: do parse _all_ core.* settings early In Git for Windows, `has_symlinks` is set to 0 by default. Therefore, we need to parse the config setting `core.symlinks` to know if it has been set to `true`. In `git init`, we must do that before copying the templates because they might contain symbolic links. Even if the support for symbolic links on Windows has not made it to upstream Git yet, we really should make sure that all the `core.*` settings are parsed before proceeding, as they might very well change the behavior of `git init` in a way the user intended. This fixes https://github.com/git-for-windows/git/issues/3414 Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- environment.c | 4 ++-- environment.h | 2 ++ setup.c | 2 +- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/environment.c b/environment.c index a770b5921d9546..b65b85a01f18cf 100644 --- a/environment.c +++ b/environment.c @@ -324,8 +324,8 @@ static enum fsync_component parse_fsync_components(const char *var, const char * return (current & ~negative) | positive; } -static int git_default_core_config(const char *var, const char *value, - const struct config_context *ctx, void *cb) +int git_default_core_config(const char *var, const char *value, + const struct config_context *ctx, void *cb) { /* This needs a better name */ if (!strcmp(var, "core.filemode")) { diff --git a/environment.h b/environment.h index 51898c99cd1e45..e61f843fdbb637 100644 --- a/environment.h +++ b/environment.h @@ -106,6 +106,8 @@ const char *strip_namespace(const char *namespaced_ref); int git_default_config(const char *, const char *, const struct config_context *, void *); +int git_default_core_config(const char *var, const char *value, + const struct config_context *ctx, void *cb); /* * TODO: All the below state either explicitly or implicitly relies on diff --git a/setup.c b/setup.c index 3a6a048620dd7d..b723f8b33931bd 100644 --- a/setup.c +++ b/setup.c @@ -2693,7 +2693,7 @@ int init_db(const char *git_dir, const char *real_git_dir, * have set up the repository format such that we can evaluate * includeIf conditions correctly in the case of re-initialization. */ - repo_config(the_repository, platform_core_config, NULL); + repo_config(the_repository, git_default_core_config, NULL); safe_create_dir(the_repository, git_dir, 0); From ac2339de65c545b23e93ecf0e10dd0c2870de8a6 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 16 Dec 2025 15:33:47 +0000 Subject: [PATCH 03/23] strbuf_readlink(): avoid calling `readlink()` twice in corner-cases The `strbuf_readlink()` function calls `readlink()`` twice if the hint argument specifies the exact size of the link target (e.g. by passing stat.st_size as returned by `lstat()`). This is necessary because `readlink(..., hint) == hint` could mean that the buffer was too small. Use `hint + 1` as buffer size to prevent this. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- strbuf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/strbuf.c b/strbuf.c index 6c3851a7f84d72..44a8f6a554ee43 100644 --- a/strbuf.c +++ b/strbuf.c @@ -578,12 +578,12 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) while (hint < STRBUF_MAXLINK) { ssize_t len; - strbuf_grow(sb, hint); - len = readlink(path, sb->buf, hint); + strbuf_grow(sb, hint + 1); + len = readlink(path, sb->buf, hint + 1); if (len < 0) { if (errno != ERANGE) break; - } else if (len < hint) { + } else if (len <= hint) { strbuf_setlen(sb, len); return 0; } From 5f09f93726e71552a0f5ffd72d488ed8dbbedee9 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 16 Dec 2025 15:33:48 +0000 Subject: [PATCH 04/23] strbuf_readlink(): support link targets that exceed PATH_MAX The `strbuf_readlink()` function refuses to read link targets that exceed PATH_MAX (even if a sufficient size was specified by the caller). As some platforms (*cough* Windows *cough*) support longer paths, remove this restriction (similar to `strbuf_getcwd()`). Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- strbuf.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/strbuf.c b/strbuf.c index 44a8f6a554ee43..fa4e30f112bb09 100644 --- a/strbuf.c +++ b/strbuf.c @@ -566,8 +566,6 @@ ssize_t strbuf_write(struct strbuf *sb, FILE *f) return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0; } -#define STRBUF_MAXLINK (2*PATH_MAX) - int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) { size_t oldalloc = sb->alloc; @@ -575,7 +573,7 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint) if (hint < 32) hint = 32; - while (hint < STRBUF_MAXLINK) { + for (;;) { ssize_t len; strbuf_grow(sb, hint + 1); From 1887b3dd06823575e37ad19b5827d467e126c6ed Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 16 Dec 2025 15:33:49 +0000 Subject: [PATCH 05/23] trim_last_path_component(): avoid hard-coding the directory separator Currently, this function hard-codes the directory separator as the forward slash. However, on Windows the backslash character is valid, too. And we want to call this function in the upcoming support for symlinks on Windows with the symlink targets (which naturally use the canonical directory separator on Windows, which is _not_ the forward slash). Prepare that function to be useful also in that context. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- lockfile.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lockfile.c b/lockfile.c index 1d5ed016828746..67082a9caaeb18 100644 --- a/lockfile.c +++ b/lockfile.c @@ -19,14 +19,14 @@ static void trim_last_path_component(struct strbuf *path) int i = path->len; /* back up past trailing slashes, if any */ - while (i && path->buf[i - 1] == '/') + while (i && is_dir_sep(path->buf[i - 1])) i--; /* * then go backwards until a slash, or the beginning of the * string */ - while (i && path->buf[i - 1] != '/') + while (i && !is_dir_sep(path->buf[i - 1])) i--; strbuf_setlen(path, i); From 6ec4ff74577f3690a11160812666e5ca800d9d65 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 12 May 2015 11:09:01 +0200 Subject: [PATCH 06/23] 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 Signed-off-by: Johannes Schindelin --- compat/mingw.c | 53 ++++++++++++++------------------------------------ 1 file changed, 15 insertions(+), 38 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index cf4f3c92e7a889..ae6826948e718d 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) From 5d83a8ab760c7fcbffe43ed82cfebd3d8eefda96 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 16 May 2015 01:18:14 +0200 Subject: [PATCH 07/23] mingw: implement `stat()` with symlink support With respect to symlinks, the current `mingw_stat()` implementation is almost identical to `mingw_lstat()`: except for the file type (`st_mode & S_IFMT`), it returns information about the link rather than the target. Implement `mingw_stat()` by opening the file handle requesting minimal permissions, and then calling `GetFileInformationByHandle()` on it. This way, all links are resolved by the Windows file system layer. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index ae6826948e718d..13970ae729872e 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1027,9 +1027,26 @@ int mingw_lstat(const char *file_name, struct stat *buf) { return do_lstat(0, file_name, buf); } + int mingw_stat(const char *file_name, struct stat *buf) { - return do_lstat(1, file_name, buf); + wchar_t wfile_name[MAX_PATH]; + HANDLE hnd; + int result; + + /* open the file and let Windows resolve the links */ + if (xutftowcs_path(wfile_name, file_name) < 0) + return -1; + hnd = CreateFileW(wfile_name, 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; + } + result = get_file_info_by_handle(hnd, buf); + CloseHandle(hnd); + return result; } int mingw_fstat(int fd, struct stat *buf) From d3953f182658bf0935ff7962bb5f04f51bef7d51 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 12 May 2015 00:58:39 +0200 Subject: [PATCH 08/23] mingw: drop the separate `do_lstat()` function With the new `mingw_stat()` implementation, `do_lstat()` is only called from `mingw_lstat()` (with the function parameter `follow == 0`). Remove the extra function and the old `mingw_stat()`-specific (`follow == 1`) logic. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 23 ++--------------------- 1 file changed, 2 insertions(+), 21 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 13970ae729872e..ec6c2801d3cbf4 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -917,15 +917,7 @@ static int has_valid_directory_prefix(wchar_t *wfilename) return 1; } -/* We keep the do_lstat code in a separate function to avoid recursion. - * 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. - */ -static int do_lstat(int follow, const char *file_name, struct stat *buf) +int mingw_lstat(const char *file_name, struct stat *buf) { WIN32_FILE_ATTRIBUTE_DATA fdata; wchar_t wfilename[MAX_PATH]; @@ -959,13 +951,7 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf) if (handle != INVALID_HANDLE_VALUE) { if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { - if (follow) { - char buffer[MAXIMUM_REPARSE_DATA_BUFFER_SIZE]; - buf->st_size = readlink(file_name, buffer, MAXIMUM_REPARSE_DATA_BUFFER_SIZE); - } else { - buf->st_mode = S_IFLNK; - } - buf->st_mode |= S_IREAD; + buf->st_mode = S_IFLNK | S_IREAD; if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) buf->st_mode |= S_IWRITE; } @@ -1023,11 +1009,6 @@ static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) return 0; } -int mingw_lstat(const char *file_name, struct stat *buf) -{ - return do_lstat(0, file_name, buf); -} - int mingw_stat(const char *file_name, struct stat *buf) { wchar_t wfile_name[MAX_PATH]; From a6355789c359f3631d5a8de7cbd1cbdbb719f8d1 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 00:17:56 +0200 Subject: [PATCH 09/23] mingw: let `mingw_lstat()` error early upon problems with reparse points When obtaining lstat information for reparse points, we need to call `FindFirstFile()` in addition to `GetFileInformationEx()` to obtain the type of the reparse point (symlink, mount point etc.). However, currently there is no error handling whatsoever if `FindFirstFile()` fails. Call `FindFirstFile()` before modifying the `stat *buf` output parameter and error out if the call fails. Note: The `FindFirstFile()` return value includes all the data that we get from `GetFileAttributesEx()`, so we could replace `GetFileAttributesEx()` with `FindFirstFile()`. We don't do that because `GetFileAttributesEx()` is about twice as fast for single files. I.e. we only pay the extra cost of calling `FindFirstFile()` in the rare case that we encounter a reparse point. Please also note that the indentation the remaining reparse point code changed, and hence the best way to look at this diff is with `--color-moved -w`. That code was _not_ moved because a subsequent commit will move it to an altogether different function, anyway. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index ec6c2801d3cbf4..23a926c7d14994 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -920,6 +920,7 @@ static int has_valid_directory_prefix(wchar_t *wfilename) int mingw_lstat(const char *file_name, struct stat *buf) { WIN32_FILE_ATTRIBUTE_DATA fdata; + WIN32_FIND_DATAW findbuf = { 0 }; wchar_t wfilename[MAX_PATH]; int wlen = xutftowcs_path(wfilename, file_name); if (wlen < 0) @@ -934,6 +935,13 @@ int mingw_lstat(const char *file_name, struct stat *buf) } if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) { + /* for reparse points, use FindFirstFile to get the reparse tag */ + if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { + HANDLE handle = FindFirstFileW(wfilename, &findbuf); + if (handle == INVALID_HANDLE_VALUE) + goto error; + FindClose(handle); + } buf->st_ino = 0; buf->st_gid = 0; buf->st_uid = 0; @@ -946,20 +954,16 @@ int mingw_lstat(const char *file_name, struct stat *buf) filetime_to_timespec(&(fdata.ftLastWriteTime), &(buf->st_mtim)); filetime_to_timespec(&(fdata.ftCreationTime), &(buf->st_ctim)); if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - WIN32_FIND_DATAW findbuf; - HANDLE handle = FindFirstFileW(wfilename, &findbuf); - if (handle != INVALID_HANDLE_VALUE) { - if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && - (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { - buf->st_mode = S_IFLNK | S_IREAD; - if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) - buf->st_mode |= S_IWRITE; - } - FindClose(handle); + if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && + (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { + buf->st_mode = S_IFLNK | S_IREAD; + if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) + buf->st_mode |= S_IWRITE; } } return 0; } +error: switch (GetLastError()) { case ERROR_ACCESS_DENIED: case ERROR_SHARING_VIOLATION: From 8b7f5a8fc7eb6e9e2cc704b5458161952d83666a Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 10 Jan 2017 23:21:56 +0100 Subject: [PATCH 10/23] mingw: teach dirent about symlinks Move the `S_IFLNK` detection to `file_attr_to_st_mode()`. Implement `DT_LNK` detection in dirent.c's `readdir()` function. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 13 +++---------- compat/win32.h | 6 ++++-- compat/win32/dirent.c | 5 ++++- 3 files changed, 11 insertions(+), 13 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 23a926c7d14994..a3a48db581df87 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -946,21 +946,14 @@ int mingw_lstat(const char *file_name, struct stat *buf) buf->st_gid = 0; buf->st_uid = 0; buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, + findbuf.dwReserved0); buf->st_size = fdata.nFileSizeLow | (((off_t)fdata.nFileSizeHigh)<<32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ filetime_to_timespec(&(fdata.ftLastAccessTime), &(buf->st_atim)); filetime_to_timespec(&(fdata.ftLastWriteTime), &(buf->st_mtim)); filetime_to_timespec(&(fdata.ftCreationTime), &(buf->st_ctim)); - if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) && - (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) { - buf->st_mode = S_IFLNK | S_IREAD; - if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY)) - buf->st_mode |= S_IWRITE; - } - } return 0; } error: @@ -1003,7 +996,7 @@ static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) buf->st_gid = 0; buf->st_uid = 0; buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, 0); buf->st_size = fdata.nFileSizeLow | (((off_t)fdata.nFileSizeHigh)<<32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ diff --git a/compat/win32.h b/compat/win32.h index a97e880757b6f1..671bcc81f93351 100644 --- a/compat/win32.h +++ b/compat/win32.h @@ -6,10 +6,12 @@ #include #endif -static inline int file_attr_to_st_mode (DWORD attr) +static inline int file_attr_to_st_mode (DWORD attr, DWORD tag) { int fMode = S_IREAD; - if (attr & FILE_ATTRIBUTE_DIRECTORY) + if ((attr & FILE_ATTRIBUTE_REPARSE_POINT) && tag == IO_REPARSE_TAG_SYMLINK) + fMode |= S_IFLNK; + else if (attr & FILE_ATTRIBUTE_DIRECTORY) fMode |= S_IFDIR; else fMode |= S_IFREG; diff --git a/compat/win32/dirent.c b/compat/win32/dirent.c index 52420ec7d4dad7..24ee9b814d6adf 100644 --- a/compat/win32/dirent.c +++ b/compat/win32/dirent.c @@ -12,7 +12,10 @@ static inline void finddata2dirent(struct dirent *ent, WIN32_FIND_DATAW *fdata) xwcstoutf(ent->d_name, fdata->cFileName, sizeof(ent->d_name)); /* Set file type, based on WIN32_FIND_DATA */ - if (fdata->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) + if ((fdata->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) + && fdata->dwReserved0 == IO_REPARSE_TAG_SYMLINK) + ent->d_type = DT_LNK; + else if (fdata->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ent->d_type = DT_DIR; else ent->d_type = DT_REG; From 1159e86dc42510297599676efee98057be857878 Mon Sep 17 00:00:00 2001 From: Bill Zissimopoulos Date: Thu, 28 May 2020 16:35:57 -0700 Subject: [PATCH 11/23] mingw: compute the correct size for symlinks in `mingw_lstat()` POSIX specifies that upon successful return from `lstat()`: "the value of the st_size member shall be set to the length of the pathname contained in the symbolic link not including any terminating null byte". Git typically doesn't trust the `stat.st_size` member of symlinks (e.g. see `strbuf_readlink()`). Therefore, it is tempting to save on the extra overhead of opening and reading the reparse point merely to calculate the exact size of the link target. This is, in fact, what Git for Windows did, from May 2015 to May 2020. At least almost: some functions take shortcuts if `st_size` is 0 (e.g. `diff_populate_filespec()`), hence Git for Windows hard-coded the length of all symlinks to MAX_PATH. This did cause problems, though, specifically in Git repositories that were also accessed by Git for Cygwin or Git for WSL. For example, doing `git reset --hard` using Git for Windows would update the size of symlinks in the index to be MAX_PATH; at a later time Git for Cygwin or Git for WSL would find that symlinks have changed size during `git status` and update the index. And then Git for Windows would think that the index needs to be updated. Even if the symlinks did not, in fact, change. To avoid that, the correct size must be determined. Signed-off-by: Bill Zissimopoulos Signed-off-by: Johannes Schindelin --- compat/mingw.c | 114 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 104 insertions(+), 10 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index a3a48db581df87..c7571951dc7bd9 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -21,6 +21,7 @@ #define SECURITY_WIN32 #include #include +#include #include #define STATUS_DELETE_PENDING ((NTSTATUS) 0xC0000056) @@ -917,10 +918,102 @@ static int has_valid_directory_prefix(wchar_t *wfilename) return 1; } +#ifndef _WINNT_H +/* + * The REPARSE_DATA_BUFFER structure is defined in the Windows DDK (in + * ntifs.h) and in MSYS1's winnt.h (which defines _WINNT_H). So define + * it ourselves if we are on MSYS2 (whose winnt.h defines _WINNT_). + */ +typedef struct _REPARSE_DATA_BUFFER { + DWORD ReparseTag; + WORD ReparseDataLength; + WORD Reserved; +#ifndef _MSC_VER + _ANONYMOUS_UNION +#endif + union { + struct { + WORD SubstituteNameOffset; + WORD SubstituteNameLength; + WORD PrintNameOffset; + WORD PrintNameLength; + ULONG Flags; + WCHAR PathBuffer[1]; + } SymbolicLinkReparseBuffer; + struct { + WORD SubstituteNameOffset; + WORD SubstituteNameLength; + WORD PrintNameOffset; + WORD PrintNameLength; + WCHAR PathBuffer[1]; + } MountPointReparseBuffer; + struct { + BYTE DataBuffer[1]; + } GenericReparseBuffer; + } DUMMYUNIONNAME; +} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER; +#endif + +static int read_reparse_point(const WCHAR *wpath, BOOL fail_on_unknown_tag, + char *tmpbuf, int *plen, DWORD *ptag) +{ + HANDLE handle; + WCHAR *wbuf; + REPARSE_DATA_BUFFER *b = alloca(MAXIMUM_REPARSE_DATA_BUFFER_SIZE); + DWORD dummy; + + /* read reparse point data */ + handle = CreateFileW(wpath, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, + FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, NULL); + if (handle == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + if (!DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, NULL, 0, b, + MAXIMUM_REPARSE_DATA_BUFFER_SIZE, &dummy, NULL)) { + errno = err_win_to_posix(GetLastError()); + CloseHandle(handle); + return -1; + } + CloseHandle(handle); + + /* get target path for symlinks or mount points (aka 'junctions') */ + switch ((*ptag = b->ReparseTag)) { + case IO_REPARSE_TAG_SYMLINK: + wbuf = (WCHAR*) (((char*) b->SymbolicLinkReparseBuffer.PathBuffer) + + b->SymbolicLinkReparseBuffer.SubstituteNameOffset); + *(WCHAR*) (((char*) wbuf) + + b->SymbolicLinkReparseBuffer.SubstituteNameLength) = 0; + break; + case IO_REPARSE_TAG_MOUNT_POINT: + wbuf = (WCHAR*) (((char*) b->MountPointReparseBuffer.PathBuffer) + + b->MountPointReparseBuffer.SubstituteNameOffset); + *(WCHAR*) (((char*) wbuf) + + b->MountPointReparseBuffer.SubstituteNameLength) = 0; + break; + default: + if (fail_on_unknown_tag) { + errno = EINVAL; + return -1; + } else { + *plen = MAX_PATH; + return 0; + } + } + + if ((*plen = + xwcstoutf(tmpbuf, normalize_ntpath(wbuf), MAX_PATH)) < 0) + return -1; + return 0; +} + int mingw_lstat(const char *file_name, struct stat *buf) { WIN32_FILE_ATTRIBUTE_DATA fdata; - WIN32_FIND_DATAW findbuf = { 0 }; + DWORD reparse_tag = 0; + int link_len = 0; wchar_t wfilename[MAX_PATH]; int wlen = xutftowcs_path(wfilename, file_name); if (wlen < 0) @@ -935,28 +1028,29 @@ int mingw_lstat(const char *file_name, struct stat *buf) } if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) { - /* for reparse points, use FindFirstFile to get the reparse tag */ + /* for reparse points, get the link tag and length */ if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) { - HANDLE handle = FindFirstFileW(wfilename, &findbuf); - if (handle == INVALID_HANDLE_VALUE) - goto error; - FindClose(handle); + char tmpbuf[MAX_PATH]; + + if (read_reparse_point(wfilename, FALSE, tmpbuf, + &link_len, &reparse_tag) < 0) + return -1; } buf->st_ino = 0; buf->st_gid = 0; buf->st_uid = 0; buf->st_nlink = 1; buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, - findbuf.dwReserved0); - buf->st_size = fdata.nFileSizeLow | - (((off_t)fdata.nFileSizeHigh)<<32); + reparse_tag); + buf->st_size = S_ISLNK(buf->st_mode) ? link_len : + fdata.nFileSizeLow | (((off_t) fdata.nFileSizeHigh) << 32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ filetime_to_timespec(&(fdata.ftLastAccessTime), &(buf->st_atim)); filetime_to_timespec(&(fdata.ftLastWriteTime), &(buf->st_mtim)); filetime_to_timespec(&(fdata.ftCreationTime), &(buf->st_ctim)); return 0; } -error: + switch (GetLastError()) { case ERROR_ACCESS_DENIED: case ERROR_SHARING_VIOLATION: From 4aeccd6656a106e537bad73c0f1c8c8c2c34992a Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 19 May 2015 21:48:55 +0200 Subject: [PATCH 12/23] mingw: factor out the retry logic In several places, Git's Windows-specific code follows the pattern where it tries to perform an operation, and retries several times when that operation fails, sleeping an increasing amount of time, before finally giving up and asking the user whether to rety (after, say, closing an editor that held a handle to a file, preventing the operation from succeeding). This logic is a bit hard to use, and inconsistent: `mingw_unlink()` and `mingw_rmdir()` duplicate the code to retry, and both of them do so incompletely. They also do not restore `errno` if the user answers 'no'. Introduce a `retry_ask_yes_no()` helper function that handles retry with small delay, asking the user, and restoring `errno`. Note that in `mingw_unlink()`, we include the `_wchmod()` call in the retry loop (which may fail if the file is locked exclusively). In `mingw_rmdir()`, we include special error handling in the retry loop. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 104 ++++++++++++++++++++++--------------------------- 1 file changed, 46 insertions(+), 58 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index c7571951dc7bd9..26e64c6a5a2997 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -28,8 +28,6 @@ #define HCAST(type, handle) ((type)(intptr_t)handle) -static const int delay[] = { 0, 1, 10, 20, 40 }; - void open_in_gdb(void) { static struct child_process cp = CHILD_PROCESS_INIT; @@ -205,15 +203,12 @@ static int read_yes_no_answer(void) return -1; } -static int ask_yes_no_if_possible(const char *format, ...) +static int ask_yes_no_if_possible(const char *format, va_list args) { char question[4096]; const char *retry_hook; - va_list args; - va_start(args, format); vsnprintf(question, sizeof(question), format, args); - va_end(args); retry_hook = mingw_getenv("GIT_ASK_YESNO"); if (retry_hook) { @@ -238,6 +233,31 @@ static int ask_yes_no_if_possible(const char *format, ...) } } +static int retry_ask_yes_no(int *tries, const char *format, ...) +{ + static const int delay[] = { 0, 1, 10, 20, 40 }; + va_list args; + int result, saved_errno = errno; + + if ((*tries) < ARRAY_SIZE(delay)) { + /* + * We assume that some other process had the file open at the wrong + * moment and retry. In order to give the other process a higher + * chance to complete its operation, we give up our time slice now. + * If we have to retry again, we do sleep a bit. + */ + Sleep(delay[*tries]); + (*tries)++; + return 1; + } + + va_start(args, format); + result = ask_yes_no_if_possible(format, args); + va_end(args); + errno = saved_errno; + return result; +} + /* Windows only */ enum hide_dotfiles_type { HIDE_DOTFILES_FALSE = 0, @@ -298,7 +318,7 @@ static wchar_t *normalize_ntpath(wchar_t *wbuf) int mingw_unlink(const char *pathname, int handle_in_use_error) { - int ret, tries = 0; + int tries = 0; wchar_t wpathname[MAX_PATH]; if (xutftowcs_path(wpathname, pathname) < 0) return -1; @@ -306,29 +326,19 @@ int mingw_unlink(const char *pathname, int handle_in_use_error) if (DeleteFileW(wpathname)) return 0; - /* read-only files cannot be removed */ - _wchmod(wpathname, 0666); - while ((ret = _wunlink(wpathname)) == -1 && tries < ARRAY_SIZE(delay)) { + do { + /* read-only files cannot be removed */ + _wchmod(wpathname, 0666); + if (!_wunlink(wpathname)) + return 0; if (!is_file_in_use_error(GetLastError())) break; if (!handle_in_use_error) - return ret; + return -1; - /* - * We assume that some other process had the source or - * destination file open at the wrong moment and retry. - * In order to give the other process a higher chance to - * complete its operation, we give up our time slice now. - * If we have to retry again, we do sleep a bit. - */ - Sleep(delay[tries]); - tries++; - } - while (ret == -1 && is_file_in_use_error(GetLastError()) && - ask_yes_no_if_possible("Unlink of file '%s' failed. " - "Should I try again?", pathname)) - ret = _wunlink(wpathname); - return ret; + } while (retry_ask_yes_no(&tries, "Unlink of file '%s' failed. " + "Should I try again?", pathname)); + return -1; } static int is_dir_empty(const wchar_t *wpath) @@ -355,7 +365,7 @@ static int is_dir_empty(const wchar_t *wpath) int mingw_rmdir(const char *pathname) { - int ret, tries = 0; + int tries = 0; wchar_t wpathname[MAX_PATH]; struct stat st; @@ -381,7 +391,11 @@ int mingw_rmdir(const char *pathname) if (xutftowcs_path(wpathname, pathname) < 0) return -1; - while ((ret = _wrmdir(wpathname)) == -1 && tries < ARRAY_SIZE(delay)) { + do { + if (!_wrmdir(wpathname)) { + invalidate_lstat_cache(); + return 0; + } if (!is_file_in_use_error(GetLastError())) errno = err_win_to_posix(GetLastError()); if (errno != EACCES) @@ -390,23 +404,9 @@ int mingw_rmdir(const char *pathname) errno = ENOTEMPTY; break; } - /* - * We assume that some other process had the source or - * destination file open at the wrong moment and retry. - * In order to give the other process a higher chance to - * complete its operation, we give up our time slice now. - * If we have to retry again, we do sleep a bit. - */ - Sleep(delay[tries]); - tries++; - } - while (ret == -1 && errno == EACCES && is_file_in_use_error(GetLastError()) && - ask_yes_no_if_possible("Deletion of directory '%s' failed. " - "Should I try again?", pathname)) - ret = _wrmdir(wpathname); - if (!ret) - invalidate_lstat_cache(); - return ret; + } while (retry_ask_yes_no(&tries, "Deletion of directory '%s' failed. " + "Should I try again?", pathname)); + return -1; } static inline int needs_hiding(const char *path) @@ -2384,20 +2384,8 @@ int mingw_rename(const char *pold, const char *pnew) SetFileAttributesW(wpnew, attrs); } } - if (tries < ARRAY_SIZE(delay) && gle == ERROR_ACCESS_DENIED) { - /* - * We assume that some other process had the source or - * destination file open at the wrong moment and retry. - * In order to give the other process a higher chance to - * complete its operation, we give up our time slice now. - * If we have to retry again, we do sleep a bit. - */ - Sleep(delay[tries]); - tries++; - goto repeat; - } if (gle == ERROR_ACCESS_DENIED && - ask_yes_no_if_possible("Rename from '%s' to '%s' failed. " + retry_ask_yes_no(&tries, "Rename from '%s' to '%s' failed. " "Should I try again?", pold, pnew)) goto repeat; From 86c07427485f6c73904fe1b637fa262468a38125 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:55:05 +0200 Subject: [PATCH 13/23] mingw: change default of `core.symlinks` to false Symlinks on Windows don't work the same way as on Unix systems. For example, there are different types of symlinks for directories and files, and unless using a recent-ish Windows version in Developer Mode, creating symlinks requires administrative privileges. By default, disable symlink support on Windows. That is, users explicitly have to enable it with `git config [--system|--global] core.symlinks true`; For convenience, `git init` (and `git clone`) will perform a test whether the current setup allows creating symlinks and will configure that setting in the repository config. The test suite ignores system / global config files. Allow testing *with* symlink support by checking if native symlinks are enabled in MSYS2 (via setting the special environment variable `MSYS=winsymlinks:nativestrict` to ask the MSYS2 runtime to enable creating symlinks). Note: This assumes that Git's test suite is run in MSYS2's Bash, which is true for the time being (an experiment to switch to BusyBox-w32 failed due to the experimental nature of BusyBox-w32). Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 26e64c6a5a2997..0fe00a5b703d07 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2862,6 +2862,15 @@ static void setup_windows_environment(void) if (!tmp && (tmp = getenv("USERPROFILE"))) setenv("HOME", tmp, 1); } + + /* + * Change 'core.symlinks' default to false, unless native symlinks are + * enabled in MSys2 (via 'MSYS=winsymlinks:nativestrict'). Thus we can + * run the test suite (which doesn't obey config files) with or without + * symlink support. + */ + if (!(tmp = getenv("MSYS")) || !strstr(tmp, "winsymlinks:nativestrict")) + has_symlinks = 0; } static void get_current_user_sid(PSID *sid, HANDLE *linked_token) From 9a0093d34bb87e4e6d5731acf39265d5bbd19431 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 16 May 2015 00:32:03 +0200 Subject: [PATCH 14/23] mingw: add symlink-specific error codes The Win32 API calls do not set `errno`; Instead, error codes for failed operations must be obtained via the `GetLastError()` function. Git would not know what to do with those error values, though, which is why Git's Windows compatibility layer translates them to `errno` values. Let's handle a couple of symlink-related error codes that will become relevant with the upcoming support for symlinks on Windows. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 0fe00a5b703d07..0e8807196fcbed 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -102,6 +102,7 @@ int err_win_to_posix(DWORD winerr) case ERROR_INVALID_PARAMETER: error = EINVAL; break; case ERROR_INVALID_PASSWORD: error = EPERM; break; case ERROR_INVALID_PRIMARY_GROUP: error = EINVAL; break; + case ERROR_INVALID_REPARSE_DATA: error = EINVAL; break; case ERROR_INVALID_SIGNAL_NUMBER: error = EINVAL; break; case ERROR_INVALID_TARGET_HANDLE: error = EIO; break; case ERROR_INVALID_WORKSTATION: error = EACCES; break; @@ -116,6 +117,7 @@ int err_win_to_posix(DWORD winerr) case ERROR_NEGATIVE_SEEK: error = ESPIPE; break; case ERROR_NOACCESS: error = EFAULT; break; case ERROR_NONE_MAPPED: error = EINVAL; break; + case ERROR_NOT_A_REPARSE_POINT: error = EINVAL; break; case ERROR_NOT_ENOUGH_MEMORY: error = ENOMEM; break; case ERROR_NOT_READY: error = EAGAIN; break; case ERROR_NOT_SAME_DEVICE: error = EXDEV; break; @@ -136,6 +138,9 @@ int err_win_to_posix(DWORD winerr) case ERROR_PIPE_NOT_CONNECTED: error = EPIPE; break; case ERROR_PRIVILEGE_NOT_HELD: error = EACCES; break; case ERROR_READ_FAULT: error = EIO; break; + case ERROR_REPARSE_ATTRIBUTE_CONFLICT: error = EINVAL; break; + case ERROR_REPARSE_TAG_INVALID: error = EINVAL; break; + case ERROR_REPARSE_TAG_MISMATCH: error = EINVAL; break; case ERROR_SEEK: error = EIO; break; case ERROR_SEEK_ON_DEVICE: error = ESPIPE; break; case ERROR_SHARING_BUFFER_EXCEEDED: error = ENFILE; break; From 5dc90f9785d8f83f39d79788a3f1b9ed8fa539dc Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:06:10 +0200 Subject: [PATCH 15/23] mingw: handle symlinks to directories in `mingw_unlink()` The `_wunlink()` and `DeleteFileW()` functions refuse to delete symlinks to directories on Windows; The error code would be `ERROR_ACCESS_DENIED` in that case. Take that error code as an indicator that we need to try `_wrmdir()` as well. In the best case, it will remove a symlink. In the worst case, it will fail with the same error code again. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index 0e8807196fcbed..b1cc30d0f13922 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -338,9 +338,16 @@ int mingw_unlink(const char *pathname, int handle_in_use_error) return 0; if (!is_file_in_use_error(GetLastError())) break; + /* + * _wunlink() / DeleteFileW() for directory symlinks fails with + * ERROR_ACCESS_DENIED (EACCES), so try _wrmdir() as well. This is the + * same error we get if a file is in use (already checked above). + */ + if (!_wrmdir(wpathname)) + return 0; + if (!handle_in_use_error) return -1; - } while (retry_ask_yes_no(&tries, "Unlink of file '%s' failed. " "Should I try again?", pathname)); return -1; From 3670a0a181f8c1198ffea6560ae81a4b4f949be2 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Tue, 19 May 2015 22:42:48 +0200 Subject: [PATCH 16/23] mingw: support renaming symlinks Older MSVCRT's `_wrename()` function cannot rename symlinks over existing files: it returns success without doing anything. Newer MSVCR*.dll versions probably do not share this problem: according to CRT sources, they just call `MoveFileEx()` with the `MOVEFILE_COPY_ALLOWED` flag. Avoid the `_wrename()` call, and go with directly calling `MoveFileEx()`, with proper error handling of course. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index b1cc30d0f13922..55f0bb478e6127 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2275,7 +2275,7 @@ int mingw_accept(int sockfd1, struct sockaddr *sa, socklen_t *sz) int mingw_rename(const char *pold, const char *pnew) { static int supports_file_rename_info_ex = 1; - DWORD attrs, gle; + DWORD attrs = INVALID_FILE_ATTRIBUTES, gle; int tries = 0; wchar_t wpold[MAX_PATH], wpnew[MAX_PATH]; int wpnew_len; @@ -2286,15 +2286,6 @@ int mingw_rename(const char *pold, const char *pnew) if (wpnew_len < 0) return -1; - /* - * Try native rename() first to get errno right. - * It is based on MoveFile(), which cannot overwrite existing files. - */ - if (!_wrename(wpold, wpnew)) - return 0; - if (errno != EEXIST) - return -1; - repeat: if (supports_file_rename_info_ex) { /* @@ -2370,13 +2361,22 @@ int mingw_rename(const char *pold, const char *pnew) * to retry. */ } else { - if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING)) + if (MoveFileExW(wpold, wpnew, + MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED)) return 0; gle = GetLastError(); } - /* TODO: translate more errors */ - if (gle == ERROR_ACCESS_DENIED && + /* revert file attributes on failure */ + if (attrs != INVALID_FILE_ATTRIBUTES) + SetFileAttributesW(wpnew, attrs); + + if (!is_file_in_use_error(gle)) { + errno = err_win_to_posix(gle); + return -1; + } + + if (attrs == INVALID_FILE_ATTRIBUTES && (attrs = GetFileAttributesW(wpnew)) != INVALID_FILE_ATTRIBUTES) { if (attrs & FILE_ATTRIBUTE_DIRECTORY) { DWORD attrsold = GetFileAttributesW(wpold); @@ -2388,16 +2388,10 @@ int mingw_rename(const char *pold, const char *pnew) return -1; } if ((attrs & FILE_ATTRIBUTE_READONLY) && - SetFileAttributesW(wpnew, attrs & ~FILE_ATTRIBUTE_READONLY)) { - if (MoveFileExW(wpold, wpnew, MOVEFILE_REPLACE_EXISTING)) - return 0; - gle = GetLastError(); - /* revert file attributes on failure */ - SetFileAttributesW(wpnew, attrs); - } + SetFileAttributesW(wpnew, attrs & ~FILE_ATTRIBUTE_READONLY)) + goto repeat; } - if (gle == ERROR_ACCESS_DENIED && - retry_ask_yes_no(&tries, "Rename from '%s' to '%s' failed. " + if (retry_ask_yes_no(&tries, "Rename from '%s' to '%s' failed. " "Should I try again?", pold, pnew)) goto repeat; From f79cf31dab8fab373978a382d71877803d89c8f7 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:17:31 +0200 Subject: [PATCH 17/23] 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 Signed-off-by: Johannes Schindelin --- compat/mingw.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index 55f0bb478e6127..5d2a8c247ce622 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -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) From 1ae9c63a89e6b35d1658042685fdec0a572b375a Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:24:41 +0200 Subject: [PATCH 18/23] mingw: implement `readlink()` Implement `readlink()` by reading NTFS reparse points via the `read_reparse_point()` function that was introduced earlier to determine the length of symlink targets. Works for symlinks and directory junctions. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw-posix.h | 3 +-- compat/mingw.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/compat/mingw-posix.h b/compat/mingw-posix.h index 0939feff27ffec..896aa976b1949b 100644 --- a/compat/mingw-posix.h +++ b/compat/mingw-posix.h @@ -121,8 +121,6 @@ struct utsname { * trivial stubs */ -static inline int readlink(const char *path UNUSED, char *buf UNUSED, size_t bufsiz UNUSED) -{ errno = ENOSYS; return -1; } static inline int symlink(const char *oldpath UNUSED, const char *newpath UNUSED) { errno = ENOSYS; return -1; } static inline int fchmod(int fildes UNUSED, mode_t mode UNUSED) @@ -197,6 +195,7 @@ int setitimer(int type, struct itimerval *in, struct itimerval *out); int sigaction(int sig, struct sigaction *in, struct sigaction *out); int link(const char *oldpath, const char *newpath); int uname(struct utsname *buf); +int readlink(const char *path, char *buf, size_t bufsiz); /* * replacements of existing functions diff --git a/compat/mingw.c b/compat/mingw.c index 5d2a8c247ce622..b407a2ac07f9d4 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2698,6 +2698,30 @@ int link(const char *oldpath, const char *newpath) return 0; } +int readlink(const char *path, char *buf, size_t bufsiz) +{ + WCHAR wpath[MAX_PATH]; + char tmpbuf[MAX_PATH]; + int len; + DWORD tag; + + if (xutftowcs_path(wpath, path) < 0) + return -1; + + if (read_reparse_point(wpath, TRUE, tmpbuf, &len, &tag) < 0) + return -1; + + /* + * Adapt to strange readlink() API: Copy up to bufsiz *bytes*, potentially + * cutting off a UTF-8 sequence. Insufficient bufsize is *not* a failure + * condition. There is no conversion function that produces invalid UTF-8, + * so convert to a (hopefully large enough) temporary buffer, then memcpy + * the requested number of bytes (including '\0' for robustness). + */ + memcpy(buf, tmpbuf, min(bufsiz, len + 1)); + return min(bufsiz, len); +} + pid_t waitpid(pid_t pid, int *status, int options) { HANDLE h = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION, From 4e0ac43ef6e04f645d501f8f46514c0dfc3f68a8 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:32:03 +0200 Subject: [PATCH 19/23] mingw: implement basic `symlink()` functionality (file symlinks only) Implement `symlink()`. This implementation always creates _file_ symlinks (remember: Windows discerns between symlinks pointing to directories and those pointing to files). Support for directory symlinks will be added in a subseqeuent commit. This implementation fails with `ENOSYS` if symlinks are disabled or unsupported. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw-posix.h | 3 +-- compat/mingw.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 2 deletions(-) diff --git a/compat/mingw-posix.h b/compat/mingw-posix.h index 896aa976b1949b..2d989fd762474e 100644 --- a/compat/mingw-posix.h +++ b/compat/mingw-posix.h @@ -121,8 +121,6 @@ struct utsname { * trivial stubs */ -static inline int symlink(const char *oldpath UNUSED, const char *newpath UNUSED) -{ errno = ENOSYS; return -1; } static inline int fchmod(int fildes UNUSED, mode_t mode UNUSED) { errno = ENOSYS; return -1; } #ifndef __MINGW64_VERSION_MAJOR @@ -195,6 +193,7 @@ int setitimer(int type, struct itimerval *in, struct itimerval *out); int sigaction(int sig, struct sigaction *in, struct sigaction *out); int link(const char *oldpath, const char *newpath); int uname(struct utsname *buf); +int symlink(const char *target, const char *link); int readlink(const char *path, char *buf, size_t bufsiz); /* diff --git a/compat/mingw.c b/compat/mingw.c index b407a2ac07f9d4..8d366794c44e55 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2698,6 +2698,34 @@ int link(const char *oldpath, const char *newpath) return 0; } +int symlink(const char *target, const char *link) +{ + wchar_t wtarget[MAX_PATH], wlink[MAX_PATH]; + int len; + + /* fail if symlinks are disabled or API is not supported (WinXP) */ + if (!has_symlinks) { + errno = ENOSYS; + return -1; + } + + if ((len = xutftowcs_path(wtarget, target)) < 0 + || xutftowcs_path(wlink, link) < 0) + return -1; + + /* convert target dir separators to backslashes */ + while (len--) + if (wtarget[len] == '/') + wtarget[len] = '\\'; + + /* create file symlink */ + if (!CreateSymbolicLinkW(wlink, wtarget, 0)) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + return 0; +} + int readlink(const char *path, char *buf, size_t bufsiz) { WCHAR wpath[MAX_PATH]; From 3d479fd47e68242b028e1bbfd0019dfb0ededac8 Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sun, 24 May 2015 01:48:35 +0200 Subject: [PATCH 20/23] mingw: add support for symlinks to directories Symlinks on Windows have a flag that indicates whether the target is a file or a directory. Symlinks of wrong type simply don't work. This even affects core Win32 APIs (e.g. `DeleteFile()` refuses to delete directory symlinks). However, `CreateFile()` with FILE_FLAG_BACKUP_SEMANTICS does work. Check the target type by first creating a tentative file symlink, opening it, and checking the type of the resulting handle. If it is a directory, recreate the symlink with the directory flag set. It is possible to create symlinks before the target exists (or in case of symlinks to symlinks: before the target type is known). If this happens, create a tentative file symlink and postpone the directory decision: keep a list of phantom symlinks to be processed whenever a new directory is created in `mingw_mkdir()`. Limitations: This algorithm may fail if a link target changes from file to directory or vice versa, or if the target directory is created in another process. It's the best Git can do, though. Signed-off-by: Karsten Blees Signed-off-by: Johannes Schindelin --- compat/mingw.c | 164 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) diff --git a/compat/mingw.c b/compat/mingw.c index 8d366794c44e55..59a32e454ed7d1 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -296,6 +296,131 @@ int mingw_core_config(const char *var, const char *value, return 0; } +static inline int is_wdir_sep(wchar_t wchar) +{ + return wchar == L'/' || wchar == L'\\'; +} + +static const wchar_t *make_relative_to(const wchar_t *path, + const wchar_t *relative_to, wchar_t *out, + size_t size) +{ + size_t i = wcslen(relative_to), len; + + /* Is `path` already absolute? */ + if (is_wdir_sep(path[0]) || + (iswalpha(path[0]) && path[1] == L':' && is_wdir_sep(path[2]))) + return path; + + while (i > 0 && !is_wdir_sep(relative_to[i - 1])) + i--; + + /* Is `relative_to` in the current directory? */ + if (!i) + return path; + + len = wcslen(path); + if (i + len + 1 > size) { + error("Could not make '%ls' relative to '%ls' (too large)", + path, relative_to); + return NULL; + } + + memcpy(out, relative_to, i * sizeof(wchar_t)); + wcscpy(out + i, path); + return out; +} + +enum phantom_symlink_result { + PHANTOM_SYMLINK_RETRY, + PHANTOM_SYMLINK_DONE, + PHANTOM_SYMLINK_DIRECTORY +}; + +/* + * Changes a file symlink to a directory symlink if the target exists and is a + * directory. + */ +static enum phantom_symlink_result +process_phantom_symlink(const wchar_t *wtarget, const wchar_t *wlink) +{ + HANDLE hnd; + BY_HANDLE_FILE_INFORMATION fdata; + wchar_t relative[MAX_PATH]; + const wchar_t *rel; + + /* check that wlink is still a file symlink */ + if ((GetFileAttributesW(wlink) + & (FILE_ATTRIBUTE_REPARSE_POINT | FILE_ATTRIBUTE_DIRECTORY)) + != FILE_ATTRIBUTE_REPARSE_POINT) + return PHANTOM_SYMLINK_DONE; + + /* make it relative, if necessary */ + rel = make_relative_to(wtarget, wlink, relative, ARRAY_SIZE(relative)); + if (!rel) + return PHANTOM_SYMLINK_DONE; + + /* let Windows resolve the link by opening it */ + hnd = CreateFileW(rel, 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 PHANTOM_SYMLINK_RETRY; + } + + if (!GetFileInformationByHandle(hnd, &fdata)) { + errno = err_win_to_posix(GetLastError()); + CloseHandle(hnd); + return PHANTOM_SYMLINK_RETRY; + } + CloseHandle(hnd); + + /* if target exists and is a file, we're done */ + if (!(fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) + return PHANTOM_SYMLINK_DONE; + + /* otherwise recreate the symlink with directory flag */ + if (DeleteFileW(wlink) && CreateSymbolicLinkW(wlink, wtarget, 1)) + return PHANTOM_SYMLINK_DIRECTORY; + + errno = err_win_to_posix(GetLastError()); + return PHANTOM_SYMLINK_RETRY; +} + +/* keep track of newly created symlinks to non-existing targets */ +struct phantom_symlink_info { + struct phantom_symlink_info *next; + wchar_t *wlink; + wchar_t *wtarget; +}; + +static struct phantom_symlink_info *phantom_symlinks = NULL; +static CRITICAL_SECTION phantom_symlinks_cs; + +static void process_phantom_symlinks(void) +{ + struct phantom_symlink_info *current, **psi; + EnterCriticalSection(&phantom_symlinks_cs); + /* process phantom symlinks list */ + psi = &phantom_symlinks; + while ((current = *psi)) { + enum phantom_symlink_result result = process_phantom_symlink( + current->wtarget, current->wlink); + if (result == PHANTOM_SYMLINK_RETRY) { + psi = ¤t->next; + } else { + /* symlink was processed, remove from list */ + *psi = current->next; + free(current); + /* if symlink was a directory, start over */ + if (result == PHANTOM_SYMLINK_DIRECTORY) + psi = &phantom_symlinks; + } + } + LeaveCriticalSection(&phantom_symlinks_cs); +} + /* Normalizes NT paths as returned by some low-level APIs. */ static wchar_t *normalize_ntpath(wchar_t *wbuf) { @@ -479,6 +604,8 @@ int mingw_mkdir(const char *path, int mode UNUSED) if (xutftowcs_path(wpath, path) < 0) return -1; ret = _wmkdir(wpath); + if (!ret) + process_phantom_symlinks(); if (!ret && needs_hiding(path)) return set_hidden_flag(wpath, 1); return ret; @@ -2723,6 +2850,42 @@ int symlink(const char *target, const char *link) errno = err_win_to_posix(GetLastError()); return -1; } + + /* convert to directory symlink if target exists */ + switch (process_phantom_symlink(wtarget, wlink)) { + case PHANTOM_SYMLINK_RETRY: { + /* if target doesn't exist, add to phantom symlinks list */ + wchar_t wfullpath[MAX_PATH]; + struct phantom_symlink_info *psi; + + /* convert to absolute path to be independent of cwd */ + len = GetFullPathNameW(wlink, MAX_PATH, wfullpath, NULL); + if (!len || len >= MAX_PATH) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + + /* over-allocate and fill phantom_symlink_info structure */ + psi = xmalloc(sizeof(struct phantom_symlink_info) + + sizeof(wchar_t) * (len + wcslen(wtarget) + 2)); + psi->wlink = (wchar_t *)(psi + 1); + wcscpy(psi->wlink, wfullpath); + psi->wtarget = psi->wlink + len + 1; + wcscpy(psi->wtarget, wtarget); + + EnterCriticalSection(&phantom_symlinks_cs); + psi->next = phantom_symlinks; + phantom_symlinks = psi; + LeaveCriticalSection(&phantom_symlinks_cs); + break; + } + case PHANTOM_SYMLINK_DIRECTORY: + /* if we created a dir symlink, process other phantom symlinks */ + process_phantom_symlinks(); + break; + default: + break; + } return 0; } @@ -3424,6 +3587,7 @@ int wmain(int argc, const wchar_t **wargv) /* initialize critical section for waitpid pinfo_t list */ InitializeCriticalSection(&pinfo_cs); + InitializeCriticalSection(&phantom_symlinks_cs); /* set up default file mode and file modes for stdin/out/err */ _fmode = _O_BINARY; From fb6aa461da7c60db07950d19a453cc75d8ddefcd Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 30 May 2017 21:50:57 +0200 Subject: [PATCH 21/23] mingw: try to create symlinks without elevated permissions As of Windows 10 Build 14972 in Developer Mode, a new flag is supported by `CreateSymbolicLink()` to create symbolic links even when running outside of an elevated session (which was previously required). This new flag is called `SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE` and has the numeric value 0x02. Previous Windows 10 versions will not understand that flag and return an `ERROR_INVALID_PARAMETER`, therefore we have to be careful to try passing that flag only when the build number indicates that it is supported. For more information about the new flag, see this blog post: https://blogs.windows.com/buildingapps/2016/12/02/symlinks-windows-10/ Signed-off-by: Johannes Schindelin --- compat/mingw.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 59a32e454ed7d1..3e2110a87ae35d 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -331,6 +331,8 @@ static const wchar_t *make_relative_to(const wchar_t *path, return out; } +static DWORD symlink_file_flags = 0, symlink_directory_flags = 1; + enum phantom_symlink_result { PHANTOM_SYMLINK_RETRY, PHANTOM_SYMLINK_DONE, @@ -381,7 +383,8 @@ process_phantom_symlink(const wchar_t *wtarget, const wchar_t *wlink) return PHANTOM_SYMLINK_DONE; /* otherwise recreate the symlink with directory flag */ - if (DeleteFileW(wlink) && CreateSymbolicLinkW(wlink, wtarget, 1)) + if (DeleteFileW(wlink) && + CreateSymbolicLinkW(wlink, wtarget, symlink_directory_flags)) return PHANTOM_SYMLINK_DIRECTORY; errno = err_win_to_posix(GetLastError()); @@ -2846,7 +2849,7 @@ int symlink(const char *target, const char *link) wtarget[len] = '\\'; /* create file symlink */ - if (!CreateSymbolicLinkW(wlink, wtarget, 0)) { + if (!CreateSymbolicLinkW(wlink, wtarget, symlink_file_flags)) { errno = err_win_to_posix(GetLastError()); return -1; } @@ -3523,6 +3526,24 @@ static void maybe_redirect_std_handles(void) GENERIC_WRITE, FILE_FLAG_NO_BUFFERING); } +static void adjust_symlink_flags(void) +{ + /* + * Starting with Windows 10 Build 14972, symbolic links can be created + * using CreateSymbolicLink() without elevation by passing the flag + * SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE (0x02) as last + * parameter, provided the Developer Mode has been enabled. Some + * earlier Windows versions complain about this flag with an + * ERROR_INVALID_PARAMETER, hence we have to test the build number + * specifically. + */ + if (GetVersion() >= 14972 << 16) { + symlink_file_flags |= 2; + symlink_directory_flags |= 2; + } + +} + #ifdef _MSC_VER #ifdef _DEBUG #include @@ -3558,6 +3579,7 @@ int wmain(int argc, const wchar_t **wargv) #endif maybe_redirect_std_handles(); + adjust_symlink_flags(); /* determine size of argv and environ conversion buffer */ maxlen = wcslen(wargv[0]); From 40c3f7f36e945c49cb8c86a431cdcca2d728ec82 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 2 Mar 2020 21:54:29 +0100 Subject: [PATCH 22/23] mingw: emulate `stat()` a little more faithfully When creating directories via `safe_create_leading_directories()`, we might encounter an already-existing directory which is not readable by the current user. To handle that situation, Git's code calls `stat()` to determine whether we're looking at a directory. In such a case, `CreateFile()` will fail, though, no matter what, and consequently `mingw_stat()` will fail, too. But POSIX semantics seem to still allow `stat()` to go forward. So let's call `mingw_lstat()` to the rescue if we fail to get a file handle due to denied permission in `mingw_stat()`, and fill the stat info that way. We need to be careful to not allow this to go forward in case that we're looking at a symbolic link: to resolve the link, we would still have to create a file handle, and we just found out that we cannot. Therefore, `stat()` still needs to fail with `EACCES` in that case. This fixes https://github.com/git-for-windows/git/issues/2531. Signed-off-by: Johannes Schindelin --- compat/mingw.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/compat/mingw.c b/compat/mingw.c index 3e2110a87ae35d..628a3941d24647 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1273,7 +1273,19 @@ int mingw_stat(const char *file_name, struct stat *buf) 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()); + DWORD err = GetLastError(); + + if (err == ERROR_ACCESS_DENIED && + !mingw_lstat(file_name, buf) && + !S_ISLNK(buf->st_mode)) + /* + * POSIX semantics state to still try to fill + * information, even if permission is denied to create + * a file handle. + */ + return 0; + + errno = err_win_to_posix(err); return -1; } result = get_file_info_by_handle(hnd, buf); From afcf2bbfcb83c542ff8e6d6d2ceef15d16e25be7 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Thu, 4 Jun 2020 23:16:07 +0200 Subject: [PATCH 23/23] mingw: special-case index entries for symlinks with buggy size In https://github.com/git-for-windows/git/pull/2637, we fixed a bug where symbolic links' target path sizes were recorded incorrectly in the index. The downside of this fix was that every user with tracked symbolic links in their checkouts would see them as modified in `git status`, but not in `git diff`, and only a `git add ` (or `git add -u`) would "fix" this. Let's do better than that: we can detect that situation and simply pretend that a symbolic link with a known bad size (or a size that just happens to be that bad size, a _very_ unlikely scenario because it would overflow our buffers due to the trailing NUL byte) means that it needs to be re-checked as if we had just checked it out. Signed-off-by: Johannes Schindelin --- read-cache.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/read-cache.c b/read-cache.c index 990d4ead0d8ae4..260f4b3b2fd55c 100644 --- a/read-cache.c +++ b/read-cache.c @@ -470,6 +470,17 @@ int ie_modified(struct index_state *istate, * then we know it is. */ if ((changed & DATA_CHANGED) && +#ifdef GIT_WINDOWS_NATIVE + /* + * Work around Git for Windows v2.27.0 fixing a bug where symlinks' + * target path lengths were not read at all, and instead recorded + * as 4096: now, all symlinks would appear as modified. + * + * So let's just special-case symlinks with a target path length + * (i.e. `sd_size`) of 4096 and force them to be re-checked. + */ + (!S_ISLNK(st->st_mode) || ce->ce_stat_data.sd_size != MAX_PATH) && +#endif (S_ISGITLINK(ce->ce_mode) || ce->ce_stat_data.sd_size != 0)) return changed;