phpstan-assert with count results in type loss

src/Analyser/TypeSpecifier.php

@@ -29,6 +29,7 @@
 use PHPStan\Reflection\ResolvedFunctionVariant;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Accessory\AccessoryArrayListType;
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
 use PHPStan\Type\Accessory\AccessoryNonFalsyStringType;
 use PHPStan\Type\Accessory\HasOffsetType;
@@ -247,7 +248,14 @@ public function specifyTypesInCondition(
 				) {
 					$argType = $scope->getType($expr->right->getArgs()[0]->value);
 					if ($argType->isArray()->yes()) {
-						$result = $result->unionWith($this->create($expr->right->getArgs()[0]->value, new NonEmptyArrayType(), $context, false, $scope, $rootExpr));
+						$newType = new NonEmptyArrayType();
+						if ($argType->isList()->yes()) {
+							$newType = AccessoryArrayListType::intersectWith($newType);
+						}
+
+						$result = $result->unionWith(
+							$this->create($expr->right->getArgs()[0]->value, $newType, $context, false, $scope, $rootExpr),
+						);
 					}
 				}
 			}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1387,6 +1387,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/falsey-empty-certainty.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8366.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7291.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-10264.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/conditional-vars.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-10189.php');
 	}

tests/PHPStan/Analyser/data/bug-10264.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Bug10264;
+
+use function PHPStan\Testing\assertType;
+
+class A
+{
+	function doFoo() {
+		/** @var list<A> $list */
+		$list = [];
+
+		assertType('list<Bug10264\A>', $list);
+
+		assert((count($list) <= 1) === true);
+		assertType('list<Bug10264\A>', $list);
+	}
+}
+
+