188407 2018-08-08 05:10:34 -0700 RegExp.exec returns wrong value with pattern "(?!(a)b)|ab" 2025-04-20 07:25:41 -0700 1 1 1 Unclassified WebKit JavaScriptCore Safari 11 Unspecified Unspecified RESOLVED CONFIGURATION CHANGED https://bugs.webkit.org/show_bug.cgi?id=210576 P2 Normal --- 1 isol2 webkit-unassigned fpizlo iKonnyaku40 msaboff ysuzuki oldest_to_newest 1448732 0 isol2 2018-08-08 05:10:34 -0700 OS: Ubuntu 16.04 x64 jsc build version: 234689 Steps to reproduce: t = new RegExp ("(?!(a)b)|ab").exec("ab"); print(t[0] == "ab"); print(t[1] == undefined); print(t) Actual results: true false ab,a Expected results: true true ab, V8, SpiderMonkey and Chakra works as expected. cinfuzz 2105412 1 iKonnyaku40 2025-03-23 06:53:39 -0700 I cannot reproduce it with the latest JSC (b2323ec6eaf613835bbaf8964d6e6d53b5310653). I think this is resolved already. 2112060 2 ysuzuki 2025-04-20 07:25:33 -0700 Yup. It seems that this is already fixed in ToT.