[PATCH 1/5] mingw: do resolve symlinks in `getcwd()`

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Dec 16, 2025, 15:33 UTC
Message-ID: <1928738b464915e3fb796145688bbfcfcc0fee3c.1765899229.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.2017.git.1765899229.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

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 <johannes.schindelin@gmx.de>
---
 compat/mingw.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index ba1b7b6dd1..7215b127cc 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1251,18 +1251,16 @@ 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))
@@ -1271,13 +1269,11 @@ 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;

-- 
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