Do not add extra parentheses when changing the return type of callable

Author: kukulich

src/Printer/Printer.php

@@ -778,6 +778,12 @@ private function printNodeFormatPreserving(Node $node, TokenIterator $originalTo
 			$mapKey = get_class($node) . '->' . $subNodeName;
 			$parenthesesNeeded = isset($this->parenthesesMap[$mapKey])
 				&& in_array(get_class($subNode), $this->parenthesesMap[$mapKey], true);
+
+			if ($subNode->getAttribute(Attribute::ORIGINAL_NODE) !== null) {
+				$parenthesesNeeded = $parenthesesNeeded
+					&& !in_array(get_class($subNode->getAttribute(Attribute::ORIGINAL_NODE)), $this->parenthesesMap[$mapKey], true);
+			}
+
 			$addParentheses = $parenthesesNeeded && !$originalTokens->hasParentheses($subStartPos, $subEndPos);
 			if ($addParentheses) {
 				$result .= '(';

tests/PHPStan/Printer/PrinterTest.php

@@ -1406,6 +1406,26 @@ public function enterNode(Node $node)
 
 			},
 		];
+
+		yield [
+			'/** @return callable(): (null|null) */',
+			'/** @return callable(): (int|null) */',
+			new class extends AbstractNodeVisitor {
+
+				public function enterNode(Node $node)
+				{
+					if ($node instanceof UnionTypeNode) {
+						$node->types = [
+							new IdentifierTypeNode('int'),
+							new IdentifierTypeNode('null'),
+						];
+					}
+
+					return $node;
+				}
+
+			},
+		];
 	}
 
 	/**