Don't check for impossible error condition in mb_strwidth

Author: alexdowad

ext/mbstring/libmbfl/mbfl/mbfilter.c

@@ -1250,10 +1250,7 @@ mbfl_strwidth(mbfl_string *string)
 		    string->encoding,
 		    &mbfl_encoding_wchar,
 		    filter_count_width, 0, &len);
-		if (filter == NULL) {
-			mbfl_convert_filter_delete(filter);
-			return -1;
-		}
+		ZEND_ASSERT(filter);
 
 		/* feed data */
 		p = string->val;

ext/mbstring/mbstring.c

@@ -2255,9 +2255,7 @@ PHP_FUNCTION(mb_strwidth)
 		RETURN_THROWS();
 	}
 
-	size_t n = mbfl_strwidth(&string);
-	ZEND_ASSERT(n != (size_t) -1);
-	RETVAL_LONG(n);
+	RETVAL_LONG(mbfl_strwidth(&string));
 }
 /* }}} */