272659 2024-04-15 00:05:51 -0700 Nested duplicate named capturing groups in regex is not syntax error 2024-04-24 09:43:28 -0700 1 1 1 Unclassified WebKit JavaScriptCore Safari 17 Mac (Apple Silicon) macOS 14 RESOLVED FIXED BrowserCompat, InRadar P2 Normal --- 1 y.ohta.z3 msaboff ahmad.saleem792 karlcow mark.lam msaboff webkit-bug-importer oldest_to_newest 2028440 0 y.ohta.z3 2024-04-15 00:05:51 -0700 When I run the following two regexes in Safari's JavaScript console, one gives a syntax error, but the other does not: But I expected both to result in a syntax error. ```js /(?:(?<x>a)|(?<x>b))(?<x>c)/; // not syntax error? /(?<x>c)(?:(?<x>a)|(?<x>b))/; // syntax error ``` I think they should both be syntax errors, since they're just swapped around. What do you think? 2030220 1 webkit-bug-importer 2024-04-22 08:54:27 -0700 <rdar://problem/126863735> 2030322 2 ahmad.saleem792 2024-04-22 13:34:22 -0700 It is reproducible in WebKit ToT as well and Chrome Canary 125 and Firefox Nightly 127 both throw 'syntax' error for first one. 2030479 3 msaboff 2024-04-23 01:13:25 -0700 I believe the first one should also be a syntax error. Investigating. 2030815 4 msaboff 2024-04-24 00:34:19 -0700 Testing a fix now. 2030829 5 msaboff 2024-04-24 02:49:19 -0700 Pull request: https://github.com/WebKit/WebKit/pull/27681 2030896 6 ews-feeder 2024-04-24 09:43:26 -0700 Committed 277928@main (93db8886b0d3): <https://commits.webkit.org/277928@main> Reviewed commits have been landed. Closing PR #27681 and removing active labels.