mingw_fopen: report ENOENT for invalid file names

On Windows, certain characters are prohibited in file names, most
prominently the colon. When fopen() is called with such an invalid file
name, the underlying Windows API actually reports a particular error,
but since there is no suitable errno value, this error is translated
to EINVAL. Detect the case and report ENOENT instead.

Signed-off-by: Johannes Sixt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: j6t

compat/mingw.c

@@ -423,6 +423,8 @@ FILE *mingw_fopen (const char *filename, const char *otype)
 		return NULL;
 	}
 	file = _wfopen(wfilename, wotype);
+	if (!file && GetLastError() == ERROR_INVALID_NAME)
+		errno = ENOENT;
 	if (file && hide && set_hidden_flag(wfilename, 1))
 		warning("could not mark '%s' as hidden.", filename);
 	return file;

t/t5580-clone-push-unc.sh

@@ -45,7 +45,7 @@ test_expect_success push '
 	test "$rev" = "$(git rev-parse --verify refs/heads/to-push)"
 '
 
-test_expect_failure 'remote nick cannot contain backslashes' '
+test_expect_success 'remote nick cannot contain backslashes' '
 	BACKSLASHED="$(pwd | tr / \\\\)" &&
 	git ls-remote "$BACKSLASHED" >out 2>err &&
 	test_i18ngrep ! "unable to access" err