Fix while loop inside another loop during scope stabilization phase

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -1288,6 +1288,22 @@ private function processStmtNode(
 		} elseif ($stmt instanceof While_) {
 			$condResult = $this->processExprNode($stmt, $stmt->cond, $scope, static function (): void {
 			}, ExpressionContext::createDeep(), $context);
+			$beforeCondBooleanType = ($this->treatPhpDocTypesAsCertain ? $scope->getType($stmt->cond) : $scope->getNativeType($stmt->cond))->toBoolean();
+			$condScope = $condResult->getFalseyScope();
+			if (!$context->isTopLevel() && $beforeCondBooleanType->isFalse()->yes()) {
+				if (!$this->polluteScopeWithLoopInitialAssignments) {
+					$scope = $condScope->mergeWith($scope);
+				}
+
+				return new StatementResult(
+					$scope,
+					$condResult->hasYield(),
+					false,
+					[],
+					$condResult->getThrowPoints(),
+					$condResult->getImpurePoints(),
+				);
+			}
 			$bodyScope = $condResult->getTruthyScope();
 
 			if ($context->isTopLevel()) {
@@ -1334,7 +1350,6 @@ private function processStmtNode(
 				$finalScope = $finalScope->mergeWith($breakExitPoint->getScope());
 			}
 
-			$beforeCondBooleanType = ($this->treatPhpDocTypesAsCertain ? $scope->getType($stmt->cond) : $scope->getNativeType($stmt->cond))->toBoolean();
 			$isIterableAtLeastOnce = $beforeCondBooleanType->isTrue()->yes();
 			$nodeCallback(new BreaklessWhileLoopNode($stmt, $finalScopeResult->getExitPoints()), $bodyScopeMaybeRan);
 
@@ -1345,7 +1360,7 @@ private function processStmtNode(
 			} else {
 				$isAlwaysTerminating = false;
 			}
-			$condScope = $condResult->getFalseyScope();
+
 			if (!$isIterableAtLeastOnce) {
 				if (!$this->polluteScopeWithLoopInitialAssignments) {
 					$condScope = $condScope->mergeWith($scope);

tests/PHPStan/Analyser/nsrt/bug-13385.php

@@ -0,0 +1,51 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13385;
+
+use function PHPStan\Testing\assertType;
+
+interface Operator {
+	public function priority(): int;
+	public function calculate(int $a, int $b): int;
+}
+
+class HelloWorld
+{
+	/**
+	 * @param list<Operator|int> $children
+	 */
+	public function calculate(array $children): int {
+		$operands  = [];
+		$operators = [];
+
+		foreach ($children as $child) {
+			if ($child instanceof Operator) {
+				while ($operators !== [] && end($operators)->priority() >= $child->priority()) {
+					$op    = array_pop($operators);
+					$left  = array_pop($operands) ?? 0;
+					$right = array_pop($operands) ?? 0;
+
+					assert(is_int($left));
+					assert(is_int($right));
+
+					$value = $op->calculate($left, $right);
+
+					assertType(Operator::class, $op);
+					assertType('int', $left);
+					assertType('int', $right);
+					assertType('int', $value);
+
+					$operands[] = $value;
+
+					assertType('non-empty-list<int>', $operands);
+				}
+
+				$operators[] = $child;
+			} else {
+				$operands[] = $child;
+			}
+		}
+
+		return count($operands) === 1 ? reset($operands) : 0;
+	}
+}