fix: reject \NN backrefs with non-octal leading digit#40
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fix: reject \NN backrefs with non-octal leading digit#40toddr-bot wants to merge 1 commit intocpan-authors:mainfrom
toddr-bot wants to merge 1 commit intocpan-authors:mainfrom
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Multi-digit backreferences like \99, \80, \89 where the leading digit is 8 or 9 have no valid octal fallback (octal digits are 0-7). Previously the parser silently produced a null character (\000) followed by literal digits. Perl correctly rejects these as "Reference to nonexistent group". The fix checks the leading digit before attempting octal fallback in the backslash-digit handler. If the digit > 7, error immediately since no valid interpretation exists. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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What
Reject multi-digit backreferences like
\99,\80,\89when no matching capture group exists and octal fallback is impossible.Why
Perl rejects these patterns as "Reference to nonexistent group" because digits 8 and 9 aren't valid octal. The parser was silently producing
\000(null) followed by literal digits — wrong output instead of an error.How
One-line guard in the backslash-digit handler: check if the leading digit > 7 before attempting octal fallback. If so, error immediately (RPe_BGROUP). Valid octal patterns like
\77and\100are unaffected.Testing
t/11errors.t(4 error cases + 2 octal fallback validations)\77,\80,\89,\98,\99,\100🤖 Generated with Claude Code
Quality Report
Changes: 2 files changed, 13 insertions(+)
Code scan: clean
Tests: passed (OK)
Branch hygiene: clean
Generated by Kōan post-mission quality pipeline