Fix static return type resolution on union class types

- In UnionType::getUnresolvedMethodPrototype(), stopped overriding each
  member's calledOnType with the full union for non-template unions
- Template union types (TemplateUnionType, TemplateBenevolentUnionType)
  still propagate the union as calledOnType to preserve template identity
- Updated existing test assertion in static-late-binding.php
- Added regression test tests/PHPStan/Analyser/nsrt/bug-11687.php

Closes phpstan/phpstan#11687

Author: phpstan-bot

src/Type/UnionType.php

@@ -581,7 +581,11 @@ public function getUnresolvedMethodPrototype(string $methodName, ClassMemberAcce
 				continue;
 			}
 
-			$methodPrototypes[] = $type->getUnresolvedMethodPrototype($methodName, $scope)->withCalledOnType($this);
+			$prototype = $type->getUnresolvedMethodPrototype($methodName, $scope);
+			if ($this instanceof TemplateType) {
+				$prototype = $prototype->withCalledOnType($this);
+			}
+			$methodPrototypes[] = $prototype;
 		}
 
 		$methodsCount = count($methodPrototypes);

tests/PHPStan/Analyser/nsrt/bug-11687.php

@@ -0,0 +1,60 @@
+<?php declare(strict_types = 1);
+
+namespace Bug11687;
+
+use function PHPStan\Testing\assertType;
+
+class A
+{
+	public static function retStaticConst(): int
+	{
+		return 1;
+	}
+
+	/**
+	 * @return static
+	 */
+	public static function retStatic()
+	{
+		return new static(); // @phpstan-ignore new.static
+	}
+}
+
+class B extends A
+{
+	/**
+	 * @return 2
+	 */
+	public static function retStaticConst(): int
+	{
+		return 2;
+	}
+
+	public function foo(): void
+	{
+		$clUnioned = mt_rand() === 0
+			? A::class
+			: X::class;
+
+		assertType('int', A::retStaticConst());
+		assertType('bool', X::retStaticConst());
+		assertType('bool|int', $clUnioned::retStaticConst());
+
+		assertType('Bug11687\A', A::retStatic());
+		assertType('bool', X::retStatic());
+		assertType('bool|Bug11687\A', $clUnioned::retStatic());
+	}
+}
+
+class X
+{
+	public static function retStaticConst(): bool
+	{
+		return false;
+	}
+
+	public static function retStatic(): bool
+	{
+		return false;
+	}
+}

tests/PHPStan/Analyser/nsrt/static-late-binding.php

@@ -85,7 +85,7 @@ public function foo(): void
         assertType('static(StaticLateBinding\B)', parent::retStatic());
         assertType('static(StaticLateBinding\B)', $this->retStatic());
         assertType('bool', X::retStatic());
-        assertType('bool|StaticLateBinding\A|StaticLateBinding\X', $clUnioned::retStatic()); // should be bool|StaticLateBinding\A https://github.com/phpstan/phpstan/issues/11687
+        assertType('bool|StaticLateBinding\A', $clUnioned::retStatic()); // should be bool|StaticLateBinding\A https://github.com/phpstan/phpstan/issues/11687
 
         assertType('StaticLateBinding\A', A::retStatic(...)());
         assertType('StaticLateBinding\B', B::retStatic(...)());