Fix defining variables in match condition

src/Analyser/MutatingScope.php

@@ -3099,6 +3099,9 @@ public function enterMatch(Expr\Match_ $expr): self
 		if ($expr->cond instanceof Variable) {
 			return $this;
 		}
+		if ($expr->cond instanceof AlwaysRememberedExpr) {
+			return $this;
+		}
 
 		$type = $this->getType($expr->cond);
 		$nativeType = $this->getNativeType($expr->cond);

src/Analyser/NodeScopeResolver.php

@@ -72,6 +72,7 @@
 use PHPStan\Node\ClosureReturnStatementsNode;
 use PHPStan\Node\DoWhileLoopConditionNode;
 use PHPStan\Node\ExecutionEndNode;
+use PHPStan\Node\Expr\AlwaysRememberedExpr;
 use PHPStan\Node\Expr\GetIterableKeyTypeExpr;
 use PHPStan\Node\Expr\GetIterableValueTypeExpr;
 use PHPStan\Node\Expr\GetOffsetValueTypeExpr;
@@ -2772,6 +2773,11 @@ static function (Node $node, Scope $scope) use ($nodeCallback): void {
 			}
 
 			$nodeCallback(new MatchExpressionNode($expr->cond, $armNodes, $expr, $matchScope), $scope);
+		} elseif ($expr instanceof AlwaysRememberedExpr) {
+			$result = $this->processExprNode($expr->getExpr(), $scope, $nodeCallback, $context);
+			$hasYield = $result->hasYield();
+			$throwPoints = $result->getThrowPoints();
+			$scope = $result->getScope();
 		} elseif ($expr instanceof Expr\Throw_) {
 			$hasYield = false;
 			$result = $this->processExprNode($expr->expr, $scope, $nodeCallback, ExpressionContext::createDeep());

tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php

@@ -954,4 +954,13 @@ public function testBug393(): void
 		$this->analyse([__DIR__ . '/data/bug-393.php'], []);
 	}
 
+	public function testBug9474(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = true;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+		$this->analyse([__DIR__ . '/data/bug-9474.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-9474.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Bug9474;
+
+class GlazedTerracotta{
+	public function getColor() : int{ return 1; }
+}
+
+class HelloWorld
+{
+	public function sayHello(): void
+	{
+		var_dump((function(GlazedTerracotta $block) : int{
+			$i = match($color = $block->getColor()){
+				1 => 1,
+				default => throw new \Exception("Unhandled dye colour " . $color)
+			};
+			echo $color;
+			return $i;
+		})(new GlazedTerracotta));
+	}
+}