[ruby-core:116686] [Ruby master Bug#20098] Wrong regexp match in ruby 3.2 and 3.3

Issue #20098 has been updated by weilandia (Nick Weiland).


Looks to be the same bug, but I cannot make it match with the backref.  Below example matches in 3.2.2 but not in 3.3.0
``` ruby
str = "------------abcdefg------------#3895912"
re = /()\1\b\w*[a-zA-Z-]*\d+[\w-]{3,}\w+\b/
re.match?(str)
```



----------------------------------------
Bug #20098: Wrong regexp match in ruby 3.2 and 3.3
https://bugs.ruby-lang.org/issues/20098#change-106699

* Author: tompng (tomoya ishida)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +MN [arm64-darwin22]
* Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
These regexp all matches in ruby 3.1.4, but not in ruby 3.3.0.
~~~ruby
p /a((.|.)|bc){,4}z/.match? 'abcbcbcbcz'
p /a(b+?c*){4,5}z/.match? 'abbbccbbbccbcbcz' # matches in ruby 3.2.2
p /a(b+?(.|.)){2,3}z/.match? 'abbbcbbbcbbbcz'
p /a(b*?(.|.)[bc]){2,5}z/.match? 'abcbbbcbcccbcz'
~~~

Adding backref (to disable optimization) makes them match.
~~~ruby
p /()\1a((.|.)|bc){,4}z/.match? 'abcbcbcbcz'
p /()\1a(b+?c*){4,5}z/.match? 'abbbccbbbccbcbcz'
p /()\1a(b+?(.|.)){2,3}z/.match? 'abbbcbbbcbbbcz'
p /()\1a(b*?(.|.)[bc]){2,5}z/.match? 'abcbbbcbcccbcz'
~~~

Found in this script https://gist.github.com/tompng/aa0706a181e9187bd79e8cec5a5f3c97




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