Fix issue 8467 intersect resolved conditional types

Author: rajyan

src/Analyser/MutatingScope.php

@@ -119,7 +119,6 @@
 use function array_map;
 use function array_merge;
 use function array_pop;
-use function array_reverse;
 use function array_slice;
 use function count;
 use function explode;
@@ -3735,7 +3734,7 @@ public function filterBySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
 		}
 
 		foreach ($scope->conditionalExpressions as $conditionalExprString => $conditionalExpressions) {
-			foreach (array_reverse($conditionalExpressions) as $conditionalExpression) {
+			foreach ($conditionalExpressions as $conditionalExpression) {
 				foreach ($conditionalExpression->getConditionExpressionTypeHolders() as $holderExprString => $conditionalTypeHolder) {
 					if (!array_key_exists($holderExprString, $specifiedExpressions) || !$specifiedExpressions[$holderExprString]->equals($conditionalTypeHolder)) {
 						continue 2;
@@ -3745,10 +3744,15 @@ public function filterBySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
 				if ($conditionalExpression->getTypeHolder()->getCertainty()->no()) {
 					unset($scope->expressionTypes[$conditionalExprString]);
 				} else {
-					$scope->expressionTypes[$conditionalExprString] = $conditionalExpression->getTypeHolder();
+					$scope->expressionTypes[$conditionalExprString] = array_key_exists($conditionalExprString, $scope->expressionTypes)
+						? new ExpressionTypeHolder(
+							$scope->expressionTypes[$conditionalExprString]->getExpr(),
+							TypeCombinator::intersect($scope->expressionTypes[$conditionalExprString]->getType(), $conditionalExpression->getTypeHolder()->getType()),
+							TrinaryLogic::maxMin($scope->expressionTypes[$conditionalExprString]->getCertainty(), $conditionalExpression->getTypeHolder()->getCertainty()),
+						)
+						: $conditionalExpression->getTypeHolder();
 					$specifiedExpressions[$conditionalExprString] = $conditionalExpression->getTypeHolder();
 				}
-				continue 2;
 			}
 		}
 

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1135,6 +1135,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8421.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/imagick-pixel.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Arrays/data/bug-8467a.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8467b.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-8467b.php

@@ -0,0 +1,56 @@
+<?php declare(strict_types = 1);
+
+namespace Bug8467b;
+
+use function PHPStan\Testing\assertType;
+
+class Test {
+	public function foo (?string $cwd, bool $initialClone = false): void {
+		if ($initialClone) {
+			$origCwd = $cwd;
+			$cwd = null;
+		}
+
+		if ($initialClone && isset($origCwd)) {
+			assertType('string', $origCwd);
+			assertType('string|null', $cwd); // could be null
+		}
+	}
+
+	/**
+	 * @param mixed[]|null $mirrors
+	 *
+	 * @return list<non-empty-string>
+	 *
+	 * @phpstan-param list<array{url: non-empty-string, preferred: bool}>|null $mirrors
+	 */
+	protected function getUrls(?string $url, ?array $mirrors, ?string $ref, ?string $type, string $urlType): array
+	{
+		if (!$url) {
+			return [];
+		}
+
+		if ($urlType === 'dist' && false !== strpos($url, '%')) {
+			assertType('string|null', $type);
+			$url = 'test';
+		}
+		assertType('non-falsy-string', $url);
+
+		$urls = [$url];
+		if ($mirrors) {
+			foreach ($mirrors as $mirror) {
+				if ($urlType === 'dist') {
+					assertType('string|null', $type);
+				} elseif ($urlType === 'source' && $type === 'git') {
+					assertType("'git'", $type);
+				} elseif ($urlType === 'source' && $type === 'hg') {
+					assertType("'hg'", $type);
+				} else {
+					continue;
+				}
+			}
+		}
+
+		return $urls;
+	}
+}