Fixed incorrect while loop logic

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -934,8 +934,8 @@ private function processStmtNode(
 			$beforeCondBooleanType = $scope->getType($stmt->cond)->toBoolean();
 			$condBooleanType = $bodyScopeMaybeRan->getType($stmt->cond)->toBoolean();
 			$isIterableAtLeastOnce = $beforeCondBooleanType->isTrue()->yes();
-			$alwaysIterates = $condBooleanType->isTrue()->yes();
-			$neverIterates = $condBooleanType->isFalse()->yes();
+			$alwaysIterates = $condBooleanType->isTrue()->yes() && $context->isTopLevel();
+			$neverIterates = $condBooleanType->isFalse()->yes() && $context->isTopLevel();
 			$nodeCallback(new BreaklessWhileLoopNode($stmt, $finalScopeResult->getExitPoints()), $bodyScopeMaybeRan);
 
 			if ($alwaysIterates) {
@@ -1008,7 +1008,7 @@ private function processStmtNode(
 				$bodyScope = $bodyScope->mergeWith($continueExitPoint->getScope());
 			}
 			$condBooleanType = $bodyScope->getType($stmt->cond)->toBoolean();
-			$alwaysIterates = $condBooleanType->isTrue()->yes();
+			$alwaysIterates = $condBooleanType->isTrue()->yes() && $context->isTopLevel();
 
 			$nodeCallback(new DoWhileLoopConditionNode($stmt->cond, $bodyScopeResult->getExitPoints()), $bodyScope);
 

tests/PHPStan/Rules/Comparison/NumberComparisonOperatorsConstantConditionRuleTest.php

@@ -155,4 +155,9 @@ public function testBug2851(): void
 		$this->analyse([__DIR__ . '/data/bug-2851.php'], []);
 	}
 
+	public function testBug8643(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-8643.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-8643.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Bug8643;
+
+function (): void {
+	$x = 0;
+
+	while ($x < 4) {
+		$y = 0;
+
+		while ($y < 6) {
+			$y += 1;
+		}
+
+		$x += 1;
+	}
+
+	echo 'done';
+};