Merge branch 'js/test-symlink-windows' into js/prep-symlink-windows

* js/test-symlink-windows:
  t7800: work around the MSYS path conversion on Windows
  t6423: introduce Windows-specific handling for symlinking to /dev/null
  t1305: skip symlink tests that do not apply to Windows
  t1006: accommodate for symlink support in MSYS2
  t0600: fix incomplete prerequisite for a test case
  t0301: another fix for Windows compatibility
  t0001: handle `diff --no-index` gracefully
  mingw: special-case `open(symlink, O_CREAT | O_EXCL)`
  apply: symbolic links lack a "trustable executable bit"
  t9700: accommodate for Windows paths

1 files changed, 14 insertions, 0 deletions

diff --git a/compat/mingw.c b/compat/mingw.c
index 939f938fe2..f09b49ff21 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -629,6 +629,7 @@ int mingw_open (const char *filename, int oflags, ...)
 	int fd, create = (oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL);
 	wchar_t wfilename[MAX_PATH];
 	open_fn_t open_fn;
+	WIN32_FILE_ATTRIBUTE_DATA fdata;
 
 	DECLARE_PROC_ADDR(ntdll.dll, NTSTATUS, NTAPI, RtlGetLastNtStatus, void);
 
@@ -653,6 +654,19 @@ int mingw_open (const char *filename, int oflags, ...)
 	else if (xutftowcs_path(wfilename, filename) < 0)
 		return -1;
 
+	/*
+	 * When `symlink` exists and is a symbolic link pointing to a
+	 * non-existing file, `_wopen(symlink, O_CREAT | O_EXCL)` would
+	 * create that file. Not what we want: Linux would say `EEXIST`
+	 * in that instance, which is therefore what Git expects.
+	 */
+	if (create &&
+	    GetFileAttributesExW(wfilename, GetFileExInfoStandard, &fdata) &&
+	    (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+		errno = EEXIST;
+		return -1;
+	}
+
 	fd = open_fn(wfilename, oflags, mode);
 
 	/*