mingw_open_existing: handle directories better

CreateFileW() requires FILE_FLAG_BACKUP_SEMANTICS to create a directory
handle [1] and errors out with ERROR_ACCESS_DENIED without this flag.
Fall back to accessing Directory handles this way.

[1] https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew#directories

This fixes https://github.com/git-for-windows/git/issues/5068

Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/compat/mingw.c b/compat/mingw.c
index 5d69ae32f4b946459c183d9106e3d212e0cb9a53..2dd5cbcaee0d5a9b50ad08d280516d3fe3a41679 100644 (file)
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -588,13 +588,24 @@ static int mingw_open_existing(const wchar_t *filename, int oflags, ...)
                             &security_attributes, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
        if (handle == INVALID_HANDLE_VALUE) {
                DWORD err = GetLastError();
+               if (err == ERROR_ACCESS_DENIED) {
+                       DWORD attrs = GetFileAttributesW(filename);
+                       if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
+                               handle = CreateFileW(filename, access,
+                                                       FILE_SHARE_WRITE | FILE_SHARE_READ | FILE_SHARE_DELETE,
+                                                       &security_attributes, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL| FILE_FLAG_BACKUP_SEMANTICS, NULL);
+               }
 
-               /* See `mingw_open_append()` for why we have this conversion. */
-               if (err == ERROR_INVALID_PARAMETER)
-                       err = ERROR_PATH_NOT_FOUND;
+               if (handle == INVALID_HANDLE_VALUE) {
+                       err = GetLastError();
 
-               errno = err_win_to_posix(err);
-               return -1;
+                       /* See `mingw_open_append()` for why we have this conversion. */
+                       if (err == ERROR_INVALID_PARAMETER)
+                               err = ERROR_PATH_NOT_FOUND;
+
+                       errno = err_win_to_posix(err);
+                       return -1;
+               }
        }
 
        fd = _open_osfhandle((intptr_t)handle, oflags | O_BINARY);