Fix

Author: VincentLanglet

bin/functionMetadata_original.php

@@ -183,6 +183,12 @@
 	'SplFileObject::ftruncate' => ['hasSideEffects' => true],
 	'SplFileObject::fwrite' => ['hasSideEffects' => true],
 
+	'SplObjectStorage::addAll' => ['hasSideEffects' => true],
+	'SplObjectStorage::attach' => ['hasSideEffects' => true],
+	'SplObjectStorage::detach' => ['hasSideEffects' => true],
+	'SplObjectStorage::removeAll' => ['hasSideEffects' => true],
+	'SplObjectStorage::removeAllExcept' => ['hasSideEffects' => true],
+
 	'XmlReader::next' => ['hasSideEffects' => true],
 	'XmlReader::read' => ['hasSideEffects' => true],
 ];

tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php

@@ -996,6 +996,11 @@ public function testBug12946(): void
 		$this->analyse([__DIR__ . '/data/bug-12946.php'], []);
 	}
 
+	public function testBug10884(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-10884.php'], []);
+	}
+
 	public function testBug13208(): void
 	{
 		$this->analyse([__DIR__ . '/data/bug-13208.php'], []);

tests/PHPStan/Rules/Comparison/data/bug-10884.php

@@ -0,0 +1,49 @@
+<?php declare(strict_types = 1);
+
+namespace Bug10884;
+
+class Cat {}
+
+/** @var \SplObjectStorage<Cat, null> $map */
+$map = new \SplObjectStorage();
+$map->attach(new Cat());
+$map->attach(new Cat());
+
+class Manager
+{
+	/**
+	 * @param SplObjectStorage<Cat, null> $map
+	 */
+	public function doSomething(\SplObjectStorage $map): void
+	{
+		/** @var \SplObjectStorage<Cat, null> $other */
+		$other = new \SplObjectStorage();
+
+		if (count($map) === 0) {
+			return;
+		}
+
+		foreach ($map as $cat) {
+			if (!$this->someCheck($cat)) {
+				continue;
+			}
+
+			$other->attach($cat);
+		}
+
+		$map->removeAll($other);
+
+		if (count($map) === 0) {
+			return;
+		}
+
+		// ok!
+	}
+
+	private function someCheck(Cat $cat): bool {
+		// just some random
+		return $cat == true;
+	}
+}
+
+(new Manager())->doSomething($map);