Retain left and right types in equal and identical expression

Author: herndlm

src/Analyser/TypeSpecifier.php

@@ -317,6 +317,9 @@ public function specifyTypesInCondition(
 if ($types !== null) {
 return $types;
 }
+
+return $this->create($expr->left, $exprLeftType, $context, false, $scope)->normalize($scope)
+->intersectWith($this->create($expr->right, $exprRightType, $context, false, $scope)->normalize($scope));
 }
 
 } elseif ($expr instanceof Node\Expr\BinaryOp\NotIdentical) {
@@ -437,7 +440,10 @@ public function specifyTypesInCondition(
 
 $leftTypes = $this->create($expr->left, $leftType, $context, false, $scope);
 $rightTypes = $this->create($expr->right, $rightType, $context, false, $scope);
-return $context->true() ? $leftTypes->unionWith($rightTypes) : $leftTypes->normalize($scope)->intersectWith($rightTypes->normalize($scope));
+
+return $context->true()
+? $leftTypes->unionWith($rightTypes)
+: $leftTypes->normalize($scope)->intersectWith($rightTypes->normalize($scope));
 } elseif ($expr instanceof Node\Expr\BinaryOp\NotEqual) {
 return $this->specifyTypesInCondition(
 $scope,

tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeMethodCallRuleTest.php

@@ -72,6 +72,14 @@ public function testRule(): void
 'Call to method ImpossibleMethodCall\Foo::isSame() with stdClass and stdClass will always evaluate to true.',
 78,
 ],
+[
+'Call to method ImpossibleMethodCall\Foo::isNotSame() with stdClass and stdClass will always evaluate to false.',
+81,
+],
+[
+'Call to method ImpossibleMethodCall\Foo::isSame() with *NEVER* and stdClass will always evaluate to false.',
+84,
+],
 ]);
 }