Fix phpstan/phpstan#14274: "Variable might not be defined" false positive

- Fixed invalidateExpression() dropping all ConditionalExpressionHolders for a
  variable when only some holders had an invalidated condition guard
- Previously, `continue 3` skipped the entire variable's holders when any single
  holder's condition guard matched the invalidated expression
- Now filters holders individually, preserving valid holders (e.g. those guarded
  by $has_staged_update) when unrelated holders (e.g. those guarded by $messages)
  are invalidated
- New regression test in tests/PHPStan/Rules/Variables/data/bug-14274.php

Author: phpstan-bot

src/Analyser/MutatingScope.php

@@ -2893,16 +2893,28 @@ public function invalidateExpression(Expr $expressionToInvalidate, bool $require
 				$invalidated = true;
 				continue;
 			}
-			foreach ($holders as $holder) {
+			$filteredHolders = [];
+			foreach ($holders as $key => $holder) {
+				$shouldKeep = true;
 				$conditionalTypeHolders = $holder->getConditionExpressionTypeHolders();
 				foreach ($conditionalTypeHolders as $conditionalTypeHolderExprString => $conditionalTypeHolder) {
 					if ($this->shouldInvalidateExpression($exprStringToInvalidate, $expressionToInvalidate, $conditionalTypeHolder->getExpr(), $conditionalTypeHolderExprString, false, $invalidatingClass)) {
 						$invalidated = true;
-						continue 3;
+						$shouldKeep = false;
+						break;
 					}
 				}
+				if (!$shouldKeep) {
+					continue;
+				}
+
+				$filteredHolders[$key] = $holder;
+			}
+			if (count($filteredHolders) <= 0) {
+				continue;
 			}
-			$newConditionalExpressions[$conditionalExprString] = $holders;
+
+			$newConditionalExpressions[$conditionalExprString] = $filteredHolders;
 		}
 
 		if (!$invalidated) {

tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php

@@ -1403,6 +1403,17 @@ public function testBug14019(): void
 		$this->analyse([__DIR__ . '/../../Analyser/nsrt/bug-14019.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.0')]
+	public function testBug14274(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14274.php'], []);
+	}
+
 	public function testBug14117(): void
 	{
 		$this->cliArgumentsVariablesRegistered = true;

tests/PHPStan/Rules/Variables/data/bug-14274.php

@@ -0,0 +1,49 @@
+<?php // lint >= 8.0
+
+declare(strict_types=1);
+
+namespace Bug14274;
+
+class PreApplyEvent {}
+
+final class ComposerPatchesValidator {
+	/**
+	 * Validates the status of the patcher plugin.
+	 */
+	public function validate(mixed $event): void {
+		$messages = [];
+
+		[$plugin_installed_in_active, $is_active_root_requirement, $active_configuration_ok] = $this->computePatcherStatus();
+		if ($event instanceof PreApplyEvent) {
+			[$plugin_installed_in_stage, $is_stage_root_requirement, $stage_configuration_ok] = $this->computePatcherStatus();
+			$has_staged_update = TRUE;
+		}
+		else {
+			// No staged update exists.
+			$has_staged_update = FALSE;
+		}
+
+		if ($has_staged_update && $plugin_installed_in_active !== $plugin_installed_in_stage) {
+			$messages[] = 'package-manager-faq-composer-patches-installed-or-removed';
+		}
+
+		// If the patcher is not listed in the runtime or dev dependencies, that's
+		// an error as well.
+		if (($plugin_installed_in_active && !$is_active_root_requirement) || ($has_staged_update && $plugin_installed_in_stage && !$is_stage_root_requirement)) {
+			$messages[] = 'It must be a root dependency.';
+		}
+
+		// If the plugin is misconfigured in either the active or stage directories,
+		// flag an error.
+		if (($plugin_installed_in_active && !$active_configuration_ok) || ($has_staged_update && $plugin_installed_in_stage && !$stage_configuration_ok)) {
+			$messages[] = 'The composer-exit-on-patch-failure key is not set to true.';
+		}
+	}
+
+	/**
+	 * @return bool[]
+	 */
+	private function computePatcherStatus(): array {
+		return [];
+	}
+}