RegexArrayShapeMatcher - Fix subject type for optional only-alternation case

Author: staabm

src/Type/Php/RegexArrayShapeMatcher.php

@@ -204,7 +204,7 @@ private function matchRegex(string $regex, ?int $flags, TrinaryLogic $wasMatched
 			}
 
 			if ($isOptionalAlternation && !$this->containsUnmatchedAsNull($flags ?? 0, $matchesAll)) {
-				$combiTypes[] = new ConstantArrayType([new ConstantIntegerType(0)], [new StringType()], [0], [], true);
+				$combiTypes[] = new ConstantArrayType([new ConstantIntegerType(0)], [$this->createSubjectValueType($flags, $matchesAll)], [0], [], true);
 			}
 
 			return TypeCombinator::union(...$combiTypes);

tests/PHPStan/Analyser/nsrt/preg_match_shapes.php

@@ -655,3 +655,10 @@ function (string $value): void
 		assertType("array{0: array{string, int<0, max>}, 1?: array{non-empty-string, int<0, max>}}", $matches);
 	}
 };
+
+function (string $value): void
+{
+	if (preg_match('/^(?:(x)|(y))*$/', $value, $matches, PREG_OFFSET_CAPTURE)) {
+		assertType("array{0: array{string, int<0, max>}, 1?: array{non-empty-string, int<0, max>}, 2?: array{non-empty-string, int<0, max>}}", $matches);
+	}
+};