[PATCH 10/18] mingw: handle symlinks to directories in `mingw_unlink()`

["Karsten Blees via GitGitGadget" <gitgitgadget@gmail.com>]

From: Karsten Blees <blees@dcon.de>

The `_wunlink()` and `DeleteFileW()` functions refuse to delete symlinks
to directories on Windows; The error code woutl be `ERROR_ACCESS_DENIED`
in that case. Take that error code as an indicator that we need to try
`_wrmdir()` as well. In the best case, it will remove a symlink. In the
worst case, it will fail with the same error code again.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 compat/mingw.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/compat/mingw.c b/compat/mingw.c
index 0e8807196f..b1cc30d0f1 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -338,9 +338,16 @@ int mingw_unlink(const char *pathname, int handle_in_use_error)
 			return 0;
 		if (!is_file_in_use_error(GetLastError()))
 			break;
+		/*
+		 * _wunlink() / DeleteFileW() for directory symlinks fails with
+		 * ERROR_ACCESS_DENIED (EACCES), so try _wrmdir() as well. This is the
+		 * same error we get if a file is in use (already checked above).
+		 */
+		if (!_wrmdir(wpathname))
+			return 0;
+
 		if (!handle_in_use_error)
 			return -1;
-
 	} while (retry_ask_yes_no(&tries, "Unlink of file '%s' failed. "
 			"Should I try again?", pathname));
 	return -1;
-- 
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