fix: prevent infinite loop on circular RV chains past MAX_DEPTH#127
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fix: prevent infinite loop on circular RV chains past MAX_DEPTH#127Koan-Bot wants to merge 4 commits into
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atoomic
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Apr 29, 2026
rv_clone_iterative lacked cycle detection and hseen registration. A circular scalar-ref pair ($a = \$b; $b = \$a) embedded deeper than MAX_DEPTH caused the walk phase to loop forever. Additionally, cloned RVs were not stored in hseen, so shared references at depth > MAX_DEPTH were duplicated instead of shared. Fix: add CLONE_FETCH guard at entry (mirrors av/hv_clone_iterative), detect cycles during the walk via linear chain scan, handle circular chains with a two-phase rebuild (placeholder + close), and register every clone in hseen during rebuild. Co-Authored-By: Claude <noreply@anthropic.com>
The mixed array/hash test used $deep_target (2500 on Windows), but each mixed level has both an AV and HV, roughly doubling per-level stack consumption during Perl's recursive SvREFCNT_dec destruction. 2500 mixed levels ≈ 10000 C stack frames, exceeding Windows's 1 MB stack. Introduce $mixed_target (1250 on Windows) which keeps destruction depth comparable to 2500 pure-array levels while still exceeding MAX_DEPTH/2 (≈400 mixed levels) to exercise the iterative clone paths.
When rv_clone_iterative's walk phase finds a cached referent via CLONE_FETCH, it must still add the current RV to chain[] before breaking. Without this, the rebuild loop has zero entries and returns the bare referent clone (e.g. IV 42) instead of an RV wrapper, breaking shared-RV identity for the second path to the same reference. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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install-with-cpm@v1 regressed on Perl 5.8-5.22 after a recent cpm update requiring Perl 5.24+. Bump to @v2 for action-based jobs and use direct `cpm install` in the Docker-based Linux matrix (where cpm is pre-installed). Matches the approach approved by @atoomic in PR garu#120. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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What
Fix infinite loop and missing hseen registration in
rv_clone_iterative.Why
A circular scalar-ref pair (
$a = \$b; $b = \$a) embedded deeper than MAX_DEPTHin a nested structure caused
rv_clone_iterativeto loop forever during its walkphase — the function lacked both cycle detection and the
CLONE_FETCHguard thatav_clone_iterativeandhv_clone_iterativealready have.Separately, cloned RVs were never stored in
hseen, so shared references atdepth > MAX_DEPTH were duplicated instead of shared (breaking reference identity).
How
CLONE_FETCHguard at function entry (mirrors av/hv iterative paths)referent, close the cycle, then apply deferred blessings
hseenviaCLONE_STOREduring rebuildTesting
New
t/24-iterative-rv-cycle.t(10 tests):alarm(10)to catch regressions as timeouts🤖 Generated with Claude Code
Quality Report
Changes: 3 files changed, 272 insertions(+), 3 deletions(-)
Code scan: clean
Tests: passed (OK)
Branch hygiene: clean
Generated by Kōan post-mission quality pipeline