Enter assignment of property fetch's var when in null coalesce operator

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -2326,8 +2326,14 @@ static function () use ($expr, $rightResult): MutatingScope {
 		} elseif ($expr instanceof Coalesce) {
 			$nonNullabilityResult = $this->ensureNonNullability($scope, $expr->left, false);
 
-			if ($expr->left instanceof PropertyFetch || $expr->left instanceof StaticPropertyFetch || $expr->left instanceof Expr\NullsafePropertyFetch) {
-				$scope = $nonNullabilityResult->getScope();
+			if ($expr->left instanceof PropertyFetch || $expr->left instanceof Expr\NullsafePropertyFetch) {
+				$scope = $this->lookForEnterVariableAssign($nonNullabilityResult->getScope(), $expr->left->var);
+			} elseif ($expr->left instanceof StaticPropertyFetch) {
+				if ($expr->left->class instanceof Expr) {
+					$scope = $this->lookForEnterVariableAssign($nonNullabilityResult->getScope(), $expr->left->class);
+				} else {
+					$scope = $nonNullabilityResult->getScope();
+				}
 			} else {
 				$scope = $this->lookForEnterVariableAssign($nonNullabilityResult->getScope(), $expr->left);
 			}

tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php

@@ -840,4 +840,14 @@ public function testBug4412(): void
 		]);
 	}
 
+	public function testBug3283(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->polluteCatchScopeWithTryAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+		$this->analyse([__DIR__ . '/data/bug-3283.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-3283.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Bug3283;
+
+function (): void
+{
+	$test = random_int(0, 10);
+
+	if ($test > 5) {
+		$user = new \stdClass;
+		$user->name = 'Thibaud';
+	}
+
+	echo $user->name ?? 'Default';
+};