Bug #22430: regex counted group with a zero-width iteration misses a match

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 4.0.7 (2026-09-15 revision 229531a6cf) +PRISM [arm64-darwin27]
• Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN

[robertmorelli (Robert Morelli)]

repro:

/\A(?:a|^){2}\z/.match?("a")     # true
/\A(?:a|^){2,3}\z/.match?("a")   # false
/\A(?:\B|a){3}\z/.match?("aa")   # false
/\A(?:^a*){2,3}\z/.match?("a")   # false

Perl and Python return true for all four. Possibly same family as #22418.