fix union types

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -1589,7 +1589,6 @@ private function getConditionalSpecifiedTypes(
 				$argumentExpr instanceof Node\Scalar
 				|| ($argumentExpr instanceof ConstFetch && in_array(strtolower($argumentExpr->name->toString()), ['true', 'false', 'null'], true))
 			)
-			&& $targetType->isConstantScalarValue()->yes()
 		) {
 			return null;
 		}

tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php

@@ -74,14 +74,6 @@ public function testImpossibleCheckTypeFunctionCall(): void
 					'Call to function is_callable() with \'nonexistentFunction\' will always evaluate to false.',
 					87,
 				],
-				[
-					'Call to function is_numeric() with \'123\' will always evaluate to true.',
-					102,
-				],
-				[
-					'Call to function is_numeric() with \'blabla\' will always evaluate to false.',
-					105,
-				],
 				[
 					'Call to function is_numeric() with 123|float will always evaluate to true.',
 					118,
@@ -231,15 +223,6 @@ public function testImpossibleCheckTypeFunctionCall(): void
 					718,
 					'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.',
 				],
-				[
-					'Call to function is_numeric() with \'123\' will always evaluate to true.',
-					718,
-				],
-				[
-					'Call to function assert() with false will always evaluate to false.',
-					719,
-					'Because the type is coming from a PHPDoc, you can turn off this check by setting <fg=cyan>treatPhpDocTypesAsCertain: false</> in your <fg=cyan>%configurationFile%</>.',
-				],
 				[
 					'Call to function is_numeric() with \'blabla\' will always evaluate to false.',
 					719,

tests/PHPStan/Rules/Comparison/data/bug-13566.php

@@ -165,5 +165,27 @@ function test(): void
 {
 	// send 404 header
 	notFound(false);
+}
+
+
+class ReturnViaUnion
+{
+	/**
+	 * @return ($exit is int ? void : never)
+	 */
+	public static function notFound(int|string $exit = 'hello world'): void
+	{
+		header('HTTP/1.1 404 Not Found', true, 404);
+
+		if (!is_int($exit)) {
+			echo '404 Not Found';
+			exit;
+		}
+	}
 
+	public function test(): void
+	{
+		// send 404 header
+		self::notFound(0);
+	}
 }