wimlib_get_error_string(): Fix return value for some invalid numbers

The function was returning NULL for unknown error codes in the range of the
array.  But it should return "Unknown error" for such codes.

diff --git a/src/util.c b/src/util.c
index 508f6f8ee357e53c523a781144d3fa9c716fd470..33c611c811558337bcd6d1b2914ba72a1be97cca 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -385,12 +385,14 @@ static const tchar *error_strings[] = {
 
 /* API function documented in wimlib.h  */
 WIMLIBAPI const tchar *
-wimlib_get_error_string(enum wimlib_error_code code)
+wimlib_get_error_string(enum wimlib_error_code _code)
 {
-       if ((unsigned int)code >= ARRAY_LEN(error_strings))
+       unsigned int code = (unsigned int)_code;
+
+       if (code >= ARRAY_LEN(error_strings) || error_strings[code] == NULL)
                return T("Unknown error");
 
-       return error_strings[(unsigned int)code];
+       return error_strings[code];
 }