Prism rejects a trailing comma in a pattern-matching loop condition before do, while parse.y accepts it#4154
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Prism rejected pattern-matching loop conditions with a trailing comma before the `do` delimiter, while parse.y accepts them. Treat `PM_TOKEN_KEYWORD_DO_LOOP` as a terminator after a trailing comma, so the loop `do` delimiter is not parsed as another pattern.
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Fixes Bug #22140.
Pattern matching syntax is parsed by
parse_pattern. When a pattern has a trailing comma, Prism checks the token after the comma to decide whether the pattern ends there or another pattern should follow.PM_TOKEN_KEYWORD_DO_LOOPwas not included in that terminator set, sowhile a in b, do endwere rejected even though parse.y accepts them. The same issue also applies tountilandforloops.This change treats
PM_TOKEN_KEYWORD_DO_LOOPas a pattern terminator after a trailing comma, so the loopdodelimiter is not parsed as the start of another pattern.