Regression: UnhandledMatchError message always NULL for variable subjects — Zend formats value (re-#23664, Zend/zend_exceptions.c)

[PurHur]

Category

bug · php-src-strict · language match

Problem

#23664 / #23678 fixed UnhandledMatchError formatting, but variable subjects now always print NULL instead of the Zend form. Literal false still formats; a false in a variable does not.

Verified 2026-07-28 (host Zend 8.2.32 vs bin/vm.php):

Repro subject	Zend 8.2	VM
match ($v) with $v = 3	Unhandled match case 3	Unhandled match case NULL
$v = 'secret-value'	Unhandled match case '...'	Unhandled match case NULL
$v = null	Unhandled match case NULL	Unhandled match case NULL (OK)
$v = true	Unhandled match case true	Unhandled match case NULL
$v = false	Unhandled match case false	Unhandled match case NULL
$v = [1]	Unhandled match case of type array	Unhandled match case NULL
literal match(false)	Unhandled match case false	Unhandled match case false (OK)

php-src reference

• php/php-src Zend/zend_execute.c — zend_match_unhandled_error()
• php/php-src Zend/zend_exceptions.c — match-case value formatting ('...' for strings; of type … for aggregates)
• Prior: Language: UnhandledMatchError message drifts from Zend — leaks strings, wrong NULL/bool/array forms (Zend/zend_vm_execute.h) #23664, Language: UnhandledMatchError still leaks string subjects — not '...' (re-#23664, Zend/zend_exceptions.c) #23678 (closed; this is a regression)

PHP implementation target

• lib/VM/MatchUnhandledSupport.php + ext/standard/phpc_match_unhandled_*.php / match lowering in lib/Compiler.php — pass the live subject into the message helper (variable path currently loses the value); JIT/AOT agree when in scope; no new runtime/*.c

Repro

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_unhandled_match_message_null.php'
# compare: php test/repro/maintainer_gap_unhandled_match_message_null.php

Inline:

<?php
foreach (['int' => 3, 'str' => 'secret-value', 'null' => null, 'true' => true, 'false' => false, 'arr' => [1]] as $label => $v) {
    try { match ($v) { 0 => 0, 'nope' => 1 }; echo "$label:no\n"; }
    catch (UnhandledMatchError $e) { echo $label, ':', $e->getMessage(), "\n"; }
}

Done when

• All six variable rows match Zend on VM (and JIT/AOT when match is lowered there)
• Literal match(false) remains correct
• Compliance .phpt guard under test/compliance/cases/
• php-src-strict; no php-compiler-strict shortcut

[PurHur]

Maintainer probe (pre-filing, 2026-07-28)

#10533 comments are locked (>2500), so recording gates here:

Gate	Status
inventory --check	green OK 6614/6614
spine coverage sync	green
north-star5-verify-fast	green
vm-driver-execute-probe	green
release-readiness --json	red — user_release_ready: no
first fail	check-helper-runtime-prelink --strict fingerprint mismatch (#24302)
gen-0	stale (2026-06-15 seed; 6784 lowering commits since)

Sibling filings this run: #24330 (extract PREFIX_IF_EXISTS re-#24311), #24331 (SplFileObject DROP_NEW_LINE trailing).

[PurHur]

claim: lane-b-implementer — starting this run

Pillar 1 snapshot (this workspace):

• inventory --check: red (doc drift vs SplArrayStorage/SplDoublyLinkedListBuiltin warning counts; not blocking this language fix)
• release-readiness: still running / previously red on helper-runtime-prelink (Foundation: helper-runtime prelink stale again — release-readiness red (re-#24302) #24336/Release blocker: committed helper-runtime cache is stale, so a clean checkout cannot compile hello world in 2 minutes #24302 — open PR Foundation: refresh helper-runtime prelink (35 stale → 0) (#24336) #24349)
• Claiming Regression: UnhandledMatchError message always NULL for variable subjects — Zend formats value (re-#23664, Zend/zend_exceptions.c) #24329 (lane B, language UnhandledMatchError variable-subject message)

[PurHur]

Merged #24353.

Fix: snapshot match subject into a fresh temp before phpc_match_unhandled_operand_message (overlay), plus Compiler guards so unhandled helpers / named CVs are not remapped onto the null match-result seed.

Verified:

php -d zend.exception_string_param_max_len=15 bin/vm.php test/repro/issue_24329_unhandled_match_message_variable.php
php -d zend.exception_string_param_max_len=15 bin/jit.php test/repro/issue_24329_unhandled_match_message_variable.php
# matches Zend for int/str/null/true/false/arr + literal false