Fix false-positive with preg_match(): Strict comparison using === between '' and non-falsy-string…ween '' and non-falsy-string

Author: staabm

src/Type/Regex/RegexGroupParser.php

@@ -367,6 +367,7 @@ private function walkGroupAst(
 		if (
 			$ast->getId() === '#concatenation'
 			&& count($children) > 0
+			&& !$walkResult->isInOptionalQuantification()
 		) {
 			$meaningfulTokens = 0;
 			foreach ($children as $child) {
@@ -400,13 +401,14 @@ private function walkGroupAst(
 			if ($min === 0) {
 				$walkResult = $walkResult->inOptionalQuantification(true);
 			}
-			if ($min >= 1) {
-				$walkResult = $walkResult
-					->nonEmpty(TrinaryLogic::createYes())
-					->inOptionalQuantification(false);
-			}
-			if ($min >= 2 && !$inAlternation) {
-				$walkResult = $walkResult->nonFalsy(TrinaryLogic::createYes());
+
+			if (!$walkResult->isInOptionalQuantification()) {
+				if ($min >= 1) {
+					$walkResult = $walkResult->nonEmpty(TrinaryLogic::createYes());
+				}
+				if ($min >= 2 && !$inAlternation) {
+					$walkResult = $walkResult->nonFalsy(TrinaryLogic::createYes());
+				}
 			}
 
 			$walkResult = $walkResult->onlyLiterals(null);

tests/PHPStan/Analyser/nsrt/preg_match_shapes.php

@@ -894,8 +894,27 @@ function testEscapedDelimiter (string $string): void {
 	}
 }
 
-function bugUnescapedDashAfterRange (string $string): void {
+function bugUnescapedDashAfterRange (string $string): void
+{
 	if (preg_match('/([0-1-y])/', $string, $matches)) {
 		assertType("array{string, non-empty-string}", $matches);
 	}
 }
+
+function bug11744(string $string): void
+{
+	if (!preg_match('~^((/[a-z]+)?)~', $string, $matches)) {
+		return;
+	}
+	assertType('array{0: string, 1: string, 2?: non-falsy-string}', $matches);
+
+	if (!preg_match('~^((/[a-z]+)?.*)~', $string, $matches)) {
+		return;
+	}
+	assertType('array{0: string, 1: string, 2?: non-falsy-string}', $matches);
+
+	if (!preg_match('~^((/[a-z]+)?.+)~', $string, $matches)) {
+		return;
+	}
+	assertType('array{0: string, 1: non-empty-string, 2?: non-falsy-string}', $matches);
+}