Keep conditional holder keys when entering a closure

enterAnonymousFunctionWithoutReflection() rebuilt each filtered holder
list with `[]`, renumbering the holders 0, 1, ... instead of keeping their
ConditionalExpressionHolder::getKey() keys. invalidateExpressionEntries()
pre-filters holders by whether their key mentions the invalidated
expression, so inside the closure a reassigned use variable never dropped
the conditionals it guards - a later match narrowed by a stale guard. The
native twin skipped the pre-filter for integer keys, so the two diverged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DEjx9cAdSfGZDQdTWKaX64

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -2597,13 +2597,13 @@ public function enterAnonymousFunctionWithoutReflection(
 				continue;
 			}
 			$filteredHolders = [];
-			foreach ($holders as $holder) {
+			foreach ($holders as $key => $holder) {
 				foreach (array_keys($holder->getConditionExpressionTypeHolders()) as $holderExprString) {
 					if (!array_key_exists($holderExprString, $useVariableNames)) {
 						continue 2;
 					}
 				}
-				$filteredHolders[] = $holder;
+				$filteredHolders[$key] = $holder;
 			}
 			if ($filteredHolders === []) {
 				continue;

tests/PHPStan/Analyser/nsrt/closure-use-conditional-guard-reassigned.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace ClosureUseConditionalGuardReassigned;
+
+use function PHPStan\Testing\assertType;
+
+function reassignedGuard(bool $c): void
+{
+	if ($c) {
+		$a = 1;
+		$b = 'x';
+	} else {
+		$a = 2;
+		$b = 'y';
+	}
+
+	$f = function () use ($a, $b): void {
+		if ($a === 1) {
+			assertType("'x'", $b);
+		}
+
+		$a = rand(1, 2);
+		if ($a === 1) {
+			assertType("'x'|'y'", $b);
+		}
+	};
+}
+
+function guardOffsetWritten(bool $c): void
+{
+	if ($c) {
+		$item = ['nested' => null, 'k' => 1];
+		$walk = 'x';
+	} else {
+		$item = ['nested' => null, 'k' => 2];
+		$walk = 'y';
+	}
+
+	$f = function () use ($item, $walk): void {
+		$item['nested'] = 1;
+		if ($item['k'] === 1) {
+			assertType("'x'|'y'", $walk);
+		}
+		if ($item === ['nested' => 1, 'k' => 1]) {
+			assertType("'x'|'y'", $walk);
+		}
+	};
+}

turbo-ext/src/MutatingScope.cpp

@@ -5380,7 +5380,9 @@ class MutatingScope
 					}
 				}
 				if (!allUsed) continue;
-				filteredHolders.push(holderEntry.value().deref());
+				zval copy;
+				ZVAL_COPY(&copy, holderEntry.value().deref().raw());
+				pt_ht_update(filteredHolders.table(), holderEntry.stringKeyOrNull(), holderEntry.indexKey(), &copy);
 			}
 			if (zend_hash_num_elements(filteredHolders.table()) == 0) continue;
 			filteredConditionalExpressions.set(conditionalExprString, zv::Val(std::move(filteredHolders)));