Properties are read when using AssignRef too

Author: ondrejmirtes

src/Node/ClassStatementsGatherer.php

@@ -155,6 +155,10 @@ private function gatherNodes(\PhpParser\Node $node, Scope $scope): void
 			$this->gatherNodes($node->var, $scope);
 			return;
 		}
+		if ($node instanceof Expr\AssignRef) {
+			$this->gatherNodes($node->expr, $scope);
+			return;
+		}
 		if ($node instanceof \PhpParser\Node\Scalar\EncapsedStringPart) {
 			return;
 		}

tests/PHPStan/Rules/DeadCode/UnusedPrivatePropertyRuleTest.php

@@ -190,4 +190,11 @@ public function testNullsafe(): void
 		$this->analyse([__DIR__ . '/data/nullsafe-unused-private-property.php'], []);
 	}
 
+	public function testBug5935(): void
+	{
+		$this->alwaysWrittenTags = [];
+		$this->alwaysReadTags = [];
+		$this->analyse([__DIR__ . '/data/bug-5935.php'], []);
+	}
+
 }

tests/PHPStan/Rules/DeadCode/data/bug-5935.php

@@ -0,0 +1,45 @@
+<?php declare(strict_types=1);
+
+namespace Bug5935;
+
+class Test
+{
+	/**
+	 * @var int[]
+	 */
+	private $arr = [];
+
+	public function test(int $id): int
+	{
+		$arr = &$this->arr;
+		if(isset($arr[$id]))
+		{
+			return $arr[$id];
+		}
+		else
+		{
+			return $arr[$id] = time();
+		}
+	}
+}
+
+class Test2
+{
+	/**
+	 * @var int[]
+	 */
+	private $arr;
+
+	public function test(int $id): int
+	{
+		$arr = &$this->arr;
+		if(isset($arr[$id]))
+		{
+			return $arr[$id];
+		}
+		else
+		{
+			return $arr[$id] = time();
+		}
+	}
+}