Merge branch 'long-paths'

Author: dscho

Documentation/config/core.txt

@@ -557,6 +557,13 @@ 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

@@ -228,6 +228,7 @@ enum hide_dotfiles_type {
 static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 static char *unset_environment_variables;
 int core_fscache;
+int core_long_paths;
 
 int mingw_core_config(const char *var, const char *value, void *cb)
 {
@@ -244,6 +245,11 @@ int mingw_core_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.longpaths")) {
+		core_long_paths = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.unsetenvvars")) {
 		free(unset_environment_variables);
 		unset_environment_variables = xstrdup(value);
@@ -281,8 +287,8 @@ 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;
 
 	/* read-only files cannot be removed */
@@ -311,7 +317,7 @@ 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);
@@ -332,8 +338,8 @@ static int is_dir_empty(const wchar_t *wpath)
 int mingw_rmdir(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;
 
 	while ((ret = _wrmdir(wpathname)) == -1 && tries < ARRAY_SIZE(delay)) {
@@ -408,9 +414,12 @@ 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];
-	if (xutftowcs_path(wpath, path) < 0)
+	wchar_t wpath[MAX_LONG_PATH];
+	/* CreateDirectoryW path limit is 248 (MAX_PATH - 8.3 file name) */
+	if (xutftowcs_path_ex(wpath, path, MAX_LONG_PATH, -1, 248,
+			core_long_paths) < 0)
 		return -1;
+
 	ret = _wmkdir(wpath);
 	if (!ret && needs_hiding(path))
 		return set_hidden_flag(wpath, 1);
@@ -483,7 +492,7 @@ int mingw_open (const char *filename, int oflags, ...)
 	va_list args;
 	unsigned mode;
 	int fd;
-	wchar_t wfilename[MAX_PATH];
+	wchar_t wfilename[MAX_LONG_PATH];
 	open_fn_t open_fn;
 
 	va_start(args, oflags);
@@ -498,7 +507,7 @@ int mingw_open (const char *filename, int oflags, ...)
 	else
 		open_fn = _wopen;
 
-	if (xutftowcs_path(wfilename, filename) < 0)
+	if (xutftowcs_long_path(wfilename, filename) < 0)
 		return -1;
 	fd = open_fn(wfilename, oflags, mode);
 
@@ -555,10 +564,10 @@ 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"))
 		filename = "nul";
-	if (xutftowcs_path(wfilename, filename) < 0 ||
+	if (xutftowcs_long_path(wfilename, filename) < 0 ||
 		xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
 		return NULL;
 	if (hide && !access(filename, F_OK) && set_hidden_flag(wfilename, 0)) {
@@ -577,10 +586,10 @@ 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"))
 		filename = "nul";
-	if (xutftowcs_path(wfilename, filename) < 0 ||
+	if (xutftowcs_long_path(wfilename, filename) < 0 ||
 		xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
 		return NULL;
 	if (hide && !access(filename, F_OK) && set_hidden_flag(wfilename, 0)) {
@@ -634,25 +643,31 @@ 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];
-	if (xutftowcs_path(wfilename, filename) < 0)
+	wchar_t wfilename[MAX_LONG_PATH];
+	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);
 }
@@ -700,8 +715,8 @@ 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)) {
@@ -772,7 +787,7 @@ 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;
@@ -788,7 +803,7 @@ 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);
@@ -872,8 +887,8 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
 	FILETIME mft, aft;
 	int fh, rc;
 	DWORD attrs;
-	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;
 
 	/* must have write permission */
@@ -934,6 +949,7 @@ 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;
 
@@ -1457,6 +1473,10 @@ 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)
@@ -1864,8 +1884,9 @@ 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;
 
 	/*
@@ -2174,9 +2195,9 @@ 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)) {
@@ -2376,6 +2397,68 @@ static void setup_windows_environment(void)
 	}
 }
 
+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) {
+		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
@@ -2534,6 +2617,9 @@ 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);