230038 2021-09-08 01:13:12 -0700 Incorrect matching of regular expressions 2021-09-15 01:14:24 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 N2107163D webkit-unassigned fpizlo msaboff webkit-bug-importer oldest_to_newest 1791406 0 437607 N2107163D 2021-09-08 01:13:12 -0700 Created attachment 437607 demo code For some regexes with backreferences and optional groupings, for example, the regex /(a)?(b)\1/ should not match the string "b", but JavaScriptCore determines the regex /(a)?(b)\1/ matching the string "b". It should be pointed out that the semantics of the regex /(a)?(b)\1/ and the regex /(a?)(b)\1/ are different. Specifically, the regex /(a)?(b)\1/ does not match the string "b", and the regex /(a?)(b)\1/ matches the string "b". 1793630 1 webkit-bug-importer 2021-09-15 01:14:24 -0700 <rdar://problem/83135746> 437607 2021-09-08 01:13:12 -0700 2021-09-08 01:13:12 -0700 demo code demo.js text/javascript 55 N2107163D dmFyIHBhdHQgPSAvKGEpPyhiKVwxLzsNCmNvbnNvbGUubG9nKHBhdHQudGVzdCgiYiIpKTsNCg==