Merge branch 'long-paths'

Author: dscho

Documentation/config/core.txt

@@ -676,6 +676,13 @@ core.fscache::
 Git for Windows uses this to bulk-read and cache lstat data of entire
 directories (instead of doing lstat file by file).
 
+core.longpaths::
+	Enable long path (> 260) support for builtin commands in Git for
+	Windows. This is disabled by default, as long paths are not supported
+	by Windows Explorer, cmd.exe and the Git for Windows tool chain
+	(msys, bash, tcl, perl...). Only enable this if you know what you're
+	doing and are prepared to live with a few quirks.
+
 core.unsetenvvars::
 	Windows-only: comma-separated list of environment variables'
 	names that need to be unset before spawning any other process.

compat/mingw.c

@@ -247,6 +247,27 @@ static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 static char *unset_environment_variables;
 int core_fscache;
 
+int are_long_paths_enabled(void)
+{
+	/* default to `false` during initialization */
+	static const int fallback = 0;
+
+	static int enabled = -1;
+
+	if (enabled < 0) {
+		/* avoid infinite recursion */
+		if (!the_repository)
+			return fallback;
+
+		if (the_repository->config &&
+		    the_repository->config->hash_initialized &&
+		    git_config_get_bool("core.longpaths", &enabled) < 0)
+			enabled = 0;
+	}
+
+	return enabled < 0 ? fallback : enabled;
+}
+
 int mingw_core_config(const char *var, const char *value,
 		      const struct config_context *ctx, void *cb)
 {
@@ -311,8 +332,8 @@ static wchar_t *normalize_ntpath(wchar_t *wbuf)
 int mingw_unlink(const char *pathname)
 {
 	int ret, tries = 0;
-	wchar_t wpathname[MAX_PATH];
-	if (xutftowcs_path(wpathname, pathname) < 0)
+	wchar_t wpathname[MAX_LONG_PATH];
+	if (xutftowcs_long_path(wpathname, pathname) < 0)
 		return -1;
 
 	if (DeleteFileW(wpathname))
@@ -344,7 +365,7 @@ static int is_dir_empty(const wchar_t *wpath)
 {
 	WIN32_FIND_DATAW findbuf;
 	HANDLE handle;
-	wchar_t wbuf[MAX_PATH + 2];
+	wchar_t wbuf[MAX_LONG_PATH + 2];
 	wcscpy(wbuf, wpath);
 	wcscat(wbuf, L"\\*");
 	handle = FindFirstFileW(wbuf, &findbuf);
@@ -365,7 +386,7 @@ static int is_dir_empty(const wchar_t *wpath)
 int mingw_rmdir(const char *pathname)
 {
 	int ret, tries = 0;
-	wchar_t wpathname[MAX_PATH];
+	wchar_t wpathname[MAX_LONG_PATH];
 	struct stat st;
 
 	/*
@@ -387,7 +408,7 @@ int mingw_rmdir(const char *pathname)
 		return -1;
 	}
 
-	if (xutftowcs_path(wpathname, pathname) < 0)
+	if (xutftowcs_long_path(wpathname, pathname) < 0)
 		return -1;
 
 	while ((ret = _wrmdir(wpathname)) == -1 && tries < ARRAY_SIZE(delay)) {
@@ -466,15 +487,18 @@ static int set_hidden_flag(const wchar_t *path, int set)
 int mingw_mkdir(const char *path, int mode)
 {
 	int ret;
-	wchar_t wpath[MAX_PATH];
+	wchar_t wpath[MAX_LONG_PATH];
 
 	if (!is_valid_win32_path(path, 0)) {
 		errno = EINVAL;
 		return -1;
 	}
 
-	if (xutftowcs_path(wpath, path) < 0)
+	/* CreateDirectoryW path limit is 248 (MAX_PATH - 8.3 file name) */
+	if (xutftowcs_path_ex(wpath, path, MAX_LONG_PATH, -1, 248,
+			      are_long_paths_enabled()) < 0)
 		return -1;
+
 	ret = _wmkdir(wpath);
 	if (!ret && needs_hiding(path))
 		return set_hidden_flag(wpath, 1);
@@ -561,7 +585,7 @@ int mingw_open (const char *filename, int oflags, ...)
 	va_list args;
 	unsigned mode;
 	int fd, create = (oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL);
-	wchar_t wfilename[MAX_PATH];
+	wchar_t wfilename[MAX_LONG_PATH];
 	open_fn_t open_fn;
 
 	va_start(args, oflags);
@@ -589,7 +613,7 @@ int mingw_open (const char *filename, int oflags, ...)
 
 	if (filename && !strcmp(filename, "/dev/null"))
 		wcscpy(wfilename, L"nul");
-	else if (xutftowcs_path(wfilename, filename) < 0)
+	else if (xutftowcs_long_path(wfilename, filename) < 0)
 		return -1;
 
 	fd = open_fn(wfilename, oflags, mode);
@@ -647,14 +671,14 @@ FILE *mingw_fopen (const char *filename, const char *otype)
 {
 	int hide = needs_hiding(filename);
 	FILE *file;
-	wchar_t wfilename[MAX_PATH], wotype[4];
+	wchar_t wfilename[MAX_LONG_PATH], wotype[4];
 	if (filename && !strcmp(filename, "/dev/null"))
 		wcscpy(wfilename, L"nul");
 	else if (!is_valid_win32_path(filename, 1)) {
 		int create = otype && strchr(otype, 'w');
 		errno = create ? EINVAL : ENOENT;
 		return NULL;
-	} else if (xutftowcs_path(wfilename, filename) < 0)
+	} else if (xutftowcs_long_path(wfilename, filename) < 0)
 		return NULL;
 
 	if (xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
@@ -676,14 +700,14 @@ FILE *mingw_freopen (const char *filename, const char *otype, FILE *stream)
 {
 	int hide = needs_hiding(filename);
 	FILE *file;
-	wchar_t wfilename[MAX_PATH], wotype[4];
+	wchar_t wfilename[MAX_LONG_PATH], wotype[4];
 	if (filename && !strcmp(filename, "/dev/null"))
 		wcscpy(wfilename, L"nul");
 	else if (!is_valid_win32_path(filename, 1)) {
 		int create = otype && strchr(otype, 'w');
 		errno = create ? EINVAL : ENOENT;
 		return NULL;
-	} else if (xutftowcs_path(wfilename, filename) < 0)
+	} else if (xutftowcs_long_path(wfilename, filename) < 0)
 		return NULL;
 
 	if (xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
@@ -733,7 +757,7 @@ ssize_t mingw_write(int fd, const void *buf, size_t len)
 		HANDLE h = (HANDLE) _get_osfhandle(fd);
 		if (GetFileType(h) != FILE_TYPE_PIPE) {
 			if (orig == EINVAL) {
-				wchar_t path[MAX_PATH];
+				wchar_t path[MAX_LONG_PATH];
 				DWORD ret = GetFinalPathNameByHandleW(h, path,
 								ARRAY_SIZE(path), 0);
 				UINT drive_type = ret > 0 && ret < ARRAY_SIZE(path) ?
@@ -770,27 +794,33 @@ ssize_t mingw_write(int fd, const void *buf, size_t len)
 
 int mingw_access(const char *filename, int mode)
 {
-	wchar_t wfilename[MAX_PATH];
+	wchar_t wfilename[MAX_LONG_PATH];
 	if (!strcmp("nul", filename) || !strcmp("/dev/null", filename))
 		return 0;
-	if (xutftowcs_path(wfilename, filename) < 0)
+	if (xutftowcs_long_path(wfilename, filename) < 0)
 		return -1;
 	/* X_OK is not supported by the MSVCRT version */
 	return _waccess(wfilename, mode & ~X_OK);
 }
 
+/* cached length of current directory for handle_long_path */
+static int current_directory_len = 0;
+
 int mingw_chdir(const char *dirname)
 {
-	wchar_t wdirname[MAX_PATH];
-	if (xutftowcs_path(wdirname, dirname) < 0)
+	int result;
+	wchar_t wdirname[MAX_LONG_PATH];
+	if (xutftowcs_long_path(wdirname, dirname) < 0)
 		return -1;
-	return _wchdir(wdirname);
+	result = _wchdir(wdirname);
+	current_directory_len = GetCurrentDirectoryW(0, NULL);
+	return result;
 }
 
 int mingw_chmod(const char *filename, int mode)
 {
-	wchar_t wfilename[MAX_PATH];
-	if (xutftowcs_path(wfilename, filename) < 0)
+	wchar_t wfilename[MAX_LONG_PATH];
+	if (xutftowcs_long_path(wfilename, filename) < 0)
 		return -1;
 	return _wchmod(wfilename, mode);
 }
@@ -838,8 +868,8 @@ static int has_valid_directory_prefix(wchar_t *wfilename)
 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)
+	wchar_t wfilename[MAX_LONG_PATH];
+	if (xutftowcs_long_path(wfilename, file_name) < 0)
 		return -1;
 
 	if (GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata)) {
@@ -910,7 +940,7 @@ static int do_lstat(int follow, const char *file_name, struct stat *buf)
 static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
 {
 	int namelen;
-	char alt_name[PATH_MAX];
+	char alt_name[MAX_LONG_PATH];
 
 	if (!do_lstat(follow, file_name, buf))
 		return 0;
@@ -926,7 +956,7 @@ static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
 		return -1;
 	while (namelen && file_name[namelen-1] == '/')
 		--namelen;
-	if (!namelen || namelen >= PATH_MAX)
+	if (!namelen || namelen >= MAX_LONG_PATH)
 		return -1;
 
 	memcpy(alt_name, file_name, namelen);
@@ -1010,10 +1040,10 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
 	FILETIME mft, aft;
 	int rc;
 	DWORD attrs;
-	wchar_t wfilename[MAX_PATH];
+	wchar_t wfilename[MAX_LONG_PATH];
 	HANDLE osfilehandle;
 
-	if (xutftowcs_path(wfilename, file_name) < 0)
+	if (xutftowcs_long_path(wfilename, file_name) < 0)
 		return -1;
 
 	/* must have write permission */
@@ -1096,6 +1126,7 @@ char *mingw_mktemp(char *template)
 	wchar_t wtemplate[MAX_PATH];
 	int offset = 0;
 
+	/* we need to return the path, thus no long paths here! */
 	if (xutftowcs_path(wtemplate, template) < 0)
 		return NULL;
 
@@ -1747,6 +1778,10 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 
 	if (*argv && !strcmp(cmd, *argv))
 		wcmd[0] = L'\0';
+	/*
+	 * Paths to executables and to the current directory do not support
+	 * long paths, therefore we cannot use xutftowcs_long_path() here.
+	 */
 	else if (xutftowcs_path(wcmd, cmd) < 0)
 		return -1;
 	if (dir && xutftowcs_path(wdir, dir) < 0)
@@ -2395,8 +2430,9 @@ int mingw_rename(const char *pold, const char *pnew)
 {
 	DWORD attrs, gle;
 	int tries = 0;
-	wchar_t wpold[MAX_PATH], wpnew[MAX_PATH];
-	if (xutftowcs_path(wpold, pold) < 0 || xutftowcs_path(wpnew, pnew) < 0)
+	wchar_t wpold[MAX_LONG_PATH], wpnew[MAX_LONG_PATH];
+	if (xutftowcs_long_path(wpold, pold) < 0 ||
+	    xutftowcs_long_path(wpnew, pnew) < 0)
 		return -1;
 
 	/*
@@ -2710,9 +2746,9 @@ int mingw_raise(int sig)
 
 int link(const char *oldpath, const char *newpath)
 {
-	wchar_t woldpath[MAX_PATH], wnewpath[MAX_PATH];
-	if (xutftowcs_path(woldpath, oldpath) < 0 ||
-		xutftowcs_path(wnewpath, newpath) < 0)
+	wchar_t woldpath[MAX_LONG_PATH], wnewpath[MAX_LONG_PATH];
+	if (xutftowcs_long_path(woldpath, oldpath) < 0 ||
+	    xutftowcs_long_path(wnewpath, newpath) < 0)
 		return -1;
 
 	if (!CreateHardLinkW(wnewpath, woldpath, NULL)) {
@@ -2780,8 +2816,8 @@ int mingw_is_mount_point(struct strbuf *path)
 {
 	WIN32_FIND_DATAW findbuf = { 0 };
 	HANDLE handle;
-	wchar_t wfilename[MAX_PATH];
-	int wlen = xutftowcs_path(wfilename, path->buf);
+	wchar_t wfilename[MAX_LONG_PATH];
+	int wlen = xutftowcs_long_path(wfilename, path->buf);
 	if (wlen < 0)
 		die(_("could not get long path for '%s'"), path->buf);
 
@@ -2926,9 +2962,9 @@ static size_t append_system_bin_dirs(char *path, size_t size)
 
 static int is_system32_path(const char *path)
 {
-	WCHAR system32[MAX_PATH], wpath[MAX_PATH];
+	WCHAR system32[MAX_LONG_PATH], wpath[MAX_LONG_PATH];
 
-	if (xutftowcs_path(wpath, path) < 0 ||
+	if (xutftowcs_long_path(wpath, path) < 0 ||
 	    !GetSystemDirectoryW(system32, ARRAY_SIZE(system32)) ||
 	    _wcsicmp(system32, wpath))
 		return 0;
@@ -3340,6 +3376,73 @@ int is_valid_win32_path(const char *path, int allow_literal_nul)
 	}
 }
 
+int handle_long_path(wchar_t *path, int len, int max_path, int expand)
+{
+	int result;
+	wchar_t buf[MAX_LONG_PATH];
+
+	/*
+	 * we don't need special handling if path is relative to the current
+	 * directory, and current directory + path don't exceed the desired
+	 * max_path limit. This should cover > 99 % of cases with minimal
+	 * performance impact (git almost always uses relative paths).
+	 */
+	if ((len < 2 || (!is_dir_sep(path[0]) && path[1] != ':')) &&
+	    (current_directory_len + len < max_path))
+		return len;
+
+	/*
+	 * handle everything else:
+	 * - absolute paths: "C:\dir\file"
+	 * - absolute UNC paths: "\\server\share\dir\file"
+	 * - absolute paths on current drive: "\dir\file"
+	 * - relative paths on other drive: "X:file"
+	 * - prefixed paths: "\\?\...", "\\.\..."
+	 */
+
+	/* convert to absolute path using GetFullPathNameW */
+	result = GetFullPathNameW(path, MAX_LONG_PATH, buf, NULL);
+	if (!result) {
+		errno = err_win_to_posix(GetLastError());
+		return -1;
+	}
+
+	/*
+	 * return absolute path if it fits within max_path (even if
+	 * "cwd + path" doesn't due to '..' components)
+	 */
+	if (result < max_path) {
+		/* Be careful not to add a drive prefix if there was none */
+		if (is_wdir_sep(path[0]) &&
+		    !is_wdir_sep(buf[0]) && buf[1] == L':' && is_wdir_sep(buf[2]))
+			wcscpy(path, buf + 2);
+		else
+			wcscpy(path, buf);
+		return result;
+	}
+
+	/* error out if we shouldn't expand the path or buf is too small */
+	if (!expand || result >= MAX_LONG_PATH - 6) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+
+	/* prefix full path with "\\?\" or "\\?\UNC\" */
+	if (buf[0] == '\\') {
+		/* ...unless already prefixed */
+		if (buf[1] == '\\' && (buf[2] == '?' || buf[2] == '.'))
+			return len;
+
+		wcscpy(path, L"\\\\?\\UNC\\");
+		wcscpy(path + 8, buf + 2);
+		return result + 6;
+	} else {
+		wcscpy(path, L"\\\\?\\");
+		wcscpy(path + 4, buf);
+		return result + 4;
+	}
+}
+
 #if !defined(_MSC_VER)
 /*
  * Disable MSVCRT command line wildcard expansion (__getmainargs called from
@@ -3501,6 +3604,9 @@ int wmain(int argc, const wchar_t **wargv)
 	/* initialize Unicode console */
 	winansi_init();
 
+	/* init length of current directory for handle_long_path */
+	current_directory_len = GetCurrentDirectoryW(0, NULL);
+
 	/* invoke the real main() using our utf8 version of argv. */
 	exit_status = main(argc, argv);