RegexArrayShapeMatcher - Fix PREG_UNMATCHED_AS_NULL with optional leading groups

Author: staabm

src/Type/Php/RegexArrayShapeMatcher.php

@@ -271,7 +271,7 @@ private function buildArrayType(
 } else {
 if ($i < $countGroups - $trailingOptionals) {
 $optional = false;
-if ($this->containsUnmatchedAsNull($flags)) {
+if ($this->containsUnmatchedAsNull($flags) && !$captureGroup->isOptional()) {
 $groupValueType = TypeCombinator::removeNull($groupValueType);
 }
 } elseif ($this->containsUnmatchedAsNull($flags)) {

tests/PHPStan/Analyser/nsrt/bug-11311.php

@@ -29,3 +29,39 @@ function unmatchedAsNullWithOptionalGroup(string $s): void {
 assertType('array{}|array{string, string|null}', $matches);
 }
 
+function bug11331a(string $url):void {
+// group a is actually optional as the entire (?:...) around it is optional
+if (preg_match('{^
+(?:
+(?<a>.+)
+)?
+(?<b>.+)}mix', $url, $matches, PREG_UNMATCHED_AS_NULL)) {
+assertType('array{0: string, a: string|null, 1: string|null, b: string, 2: string}', $matches);
+}
+}
+
+function bug11331b(string $url):void {
+if (preg_match('{^
+(?:
+(?<a>.+)
+)?
+(?<b>.+)?}mix', $url, $matches, PREG_UNMATCHED_AS_NULL)) {
+assertType('array{0: string, a: string|null, 1: string|null, b: string|null, 2: string|null}', $matches);
+}
+}
+
+function bug11331c(string $url):void {
+if (preg_match('{^
+(?:
+(?:https?|git)://([^/]+)/ (?# group 1 here can be null if group 2 matches)
+| (?# the alternation making it so that only either should match)
+git@([^:]+):/? (?# group 2 here can be null if group 1 matches)
+)
+([^/]+)
+/
+([^/]+?)
+(?:\.git|/)?
+$}x', $url, $matches, PREG_UNMATCHED_AS_NULL)) {
+assertType('array{string, string|null, string|null, string, string}', $matches);
+}
+}