Ignore the new Foo() exactness flavour when comparing generic type arguments for variance

src/Type/Generic/TemplateTypeVariance.php

@@ -232,11 +232,11 @@ public function isValidVariance(TemplateType $templateType, Type $a, Type $b, bo
 		}
 
 		if ($this->covariant()) {
-			return $a->isSuperTypeOf($b);
+			return self::compareTypeArguments($a, $b);
 		}
 
 		if ($this->contravariant()) {
-			return $b->isSuperTypeOf($a);
+			return self::compareTypeArguments($b, $a);
 		}
 
 		if ($this->bivariant()) {
@@ -246,6 +246,19 @@ public function isValidVariance(TemplateType $templateType, Type $a, Type $b, bo
 		throw new ShouldNotHappenException();
 	}
 
+	/**
+	 * The "exactly this class" flavour of a `new Foo()` value cannot be written in a
+	 * PHPDoc type argument, and `Foo` with the flavour is only a maybe-supertype of a
+	 * plain `Foo`. Comparing the two directly would make a type argument carrying the
+	 * flavour unmatchable against the very same written type - the invariant branch
+	 * above does not have the problem because equals() ignores the flavour.
+	 */
+	private static function compareTypeArguments(Type $super, Type $sub): IsSuperTypeOfResult
+	{
+		return TemplateTypeHelper::removeFinalByKeywordOverrides($super)
+			->isSuperTypeOf(TemplateTypeHelper::removeFinalByKeywordOverrides($sub));
+	}
+
 	public function equals(self $other): bool
 	{
 		return $other->value === $this->value;

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -4452,6 +4452,14 @@ public function testBug8441(): void
 	}
 
 	#[RequiresPhp('>= 8.1.0')]
+	public function testBug15235(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkNullables = true;
+		$this->checkUnionTypes = true;
+		$this->analyse([__DIR__ . '/data/bug-15235.php'], []);
+	}
+
 	public function testBug15166(): void
 	{
 		$this->checkThisOnly = false;

tests/PHPStan/Rules/Methods/data/bug-15235.php

@@ -0,0 +1,173 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug15235;
+
+/**
+ * @template T of object
+ */
+class A
+{
+	/**
+	 * @param T $object
+	 */
+	public function __construct(public object $object) {}
+}
+
+class B
+{
+	/**
+	 * @param A<covariant static> $a
+	 */
+	public function method(A $a): void {}
+
+	/**
+	 * @param A<static> $a
+	 */
+	public function invariant(A $a): void {}
+
+	/**
+	 * @param A<contravariant static> $a
+	 */
+	public function contravariant(A $a): void {}
+}
+
+class D
+{
+	public function inconsistent(B $b): void
+	{
+		$b->method(new A($b));
+	}
+}
+
+function fromNew(): void
+{
+	$b = new B();
+	$b->method(new A($b));
+	$b->invariant(new A($b));
+	$b->contravariant(new A($b));
+}
+
+function fromGetClass(B $b): void
+{
+	if (get_class($b) !== B::class) {
+		return;
+	}
+
+	$b->method(new A($b));
+}
+
+/** @template-covariant T of object */
+class Covariant
+{
+	/** @param T $object */
+	public function __construct(public object $object) {}
+}
+
+/** @template-contravariant T of object */
+class Contravariant
+{
+	/** @param T $object */
+	public function set(object $object): void {}
+}
+
+class E
+{
+	/** @param Covariant<static> $c */
+	public function declaredCovariant(Covariant $c): void {}
+
+	/** @param Contravariant<static> $c */
+	public function declaredContravariant(Contravariant $c): void {}
+
+	/** @param \Traversable<int, static> $it */
+	public function traversable(\Traversable $it): void {}
+
+	/** @return Covariant<static> */
+	public function makeCovariant(): Covariant
+	{
+		return new Covariant($this);
+	}
+
+	/** @return Wrapper<static> */
+	public function makeWrapper(): Wrapper
+	{
+		return new Wrapper($this);
+	}
+}
+
+class Consumer
+{
+	/** @param Covariant<E> $c */
+	public function takesCovariant(Covariant $c): void {}
+
+	/** @param Wrapper<contravariant E> $wrapper */
+	public function takesContravariantWrapper(Wrapper $wrapper): void {}
+
+	/** @param Wrapper<Covariant<E>> $wrapper */
+	public function takesNested(Wrapper $wrapper): void {}
+}
+
+/**
+ * @param Covariant<E> $covariant
+ * @param Contravariant<E> $contravariant
+ * @param \Traversable<int, E> $traversable
+ */
+function declaredVariances(Covariant $covariant, Contravariant $contravariant, \Traversable $traversable): void
+{
+	$e = new E();
+	$e->declaredCovariant($covariant);
+	$e->declaredContravariant($contravariant);
+	$e->traversable($traversable);
+}
+
+function flavourOnTheArgumentSide(Consumer $consumer): void
+{
+	$e = new E();
+	$consumer->takesCovariant($e->makeCovariant());
+	$consumer->takesContravariantWrapper($e->makeWrapper());
+}
+
+/** @template T of object */
+class Wrapper
+{
+	/** @param T $object */
+	public function __construct(public object $object) {}
+}
+
+function nestedInGenericType(Consumer $consumer): void
+{
+	$e = new E();
+	$consumer->takesNested(new Wrapper($e->makeCovariant()));
+}
+
+class Composite
+{
+	/** @param Covariant<static>|null $c */
+	public function inUnion(?Covariant $c): void {}
+
+	/** @param array<int, Covariant<static>> $c */
+	public function inArray(array $c): void {}
+
+	/** @param Covariant<Covariant<static>> $c */
+	public function nested(Covariant $c): void {}
+
+	/** @param Wrapper<Covariant<static>> $c */
+	public function nestedInvariant(Wrapper $c): void {}
+}
+
+/**
+ * @param Covariant<Composite> $covariant
+ * @param array<int, Covariant<Composite>> $array
+ * @param Covariant<Covariant<Composite>> $nested
+ * @param Wrapper<Covariant<Composite>> $nestedInvariant
+ */
+function compositeShapes(Covariant $covariant, array $array, Covariant $nested, Wrapper $nestedInvariant): void
+{
+	$composite = new Composite();
+	$composite->inUnion($covariant);
+	$composite->inUnion(null);
+	$composite->inArray($array);
+	$composite->nested($nested);
+	$composite->nestedInvariant($nestedInvariant);
+}

tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php

@@ -1096,6 +1096,11 @@ public function testBug8441(): void
 	}
 
 	#[RequiresPhp('>= 8.1.0')]
+	public function testBug15235(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15235.php'], []);
+	}
+
 	public function testBug15166(): void
 	{
 		$this->analyse([__DIR__ . '/data/bug-15166.php'], []);

tests/PHPStan/Rules/Properties/data/bug-15235.php

@@ -0,0 +1,45 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug15235Properties;
+
+/**
+ * @template T of object
+ */
+class A
+{
+	/**
+	 * @param T $object
+	 */
+	public function __construct(public object $object) {}
+}
+
+/** @template-covariant T of object */
+class Covariant
+{
+	/** @param T $object */
+	public function __construct(public object $object) {}
+}
+
+class B
+{
+	/** @var A<covariant static>|null */
+	public ?A $callSiteVariance = null;
+
+	/** @var Covariant<static>|null */
+	public ?Covariant $declaredVariance = null;
+}
+
+function fromParameter(B $b): void
+{
+	$b->callSiteVariance = new A($b);
+	$b->declaredVariance = new Covariant($b);
+}
+
+function fromNew(): void
+{
+	$b = new B();
+	$b->callSiteVariance = new A($b);
+	$b->declaredVariance = new Covariant($b);
+}