From 1e6977af1157db2448b1b74aad7ec76232630e94 Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Thu, 19 Dec 2024 20:31:20 +0100
Subject: [PATCH] Fix preg_match() group containing start/end meta characters

---
 src/Type/Regex/RegexGroupParser.php       |  2 +-
 tests/PHPStan/Analyser/nsrt/bug-12297.php | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 tests/PHPStan/Analyser/nsrt/bug-12297.php

diff --git a/src/Type/Regex/RegexGroupParser.php b/src/Type/Regex/RegexGroupParser.php
index beea95bce0..a8a9755e8a 100644
--- a/src/Type/Regex/RegexGroupParser.php
+++ b/src/Type/Regex/RegexGroupParser.php
@@ -527,7 +527,7 @@ private function isMaybeEmptyNode(TreeNode $node, string $patternModifiers, bool
 			if ($literal !== '' && $literal !== '0') {
 				$isNonFalsy = true;
 			}
-			return false;
+			return $literal === '';
 		}
 
 		foreach ($node->getChildren() as $child) {
diff --git a/tests/PHPStan/Analyser/nsrt/bug-12297.php b/tests/PHPStan/Analyser/nsrt/bug-12297.php
new file mode 100644
index 0000000000..4a956e42a4
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-12297.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace Bug12297;
+
+use function PHPStan\Testing\assertType;
+
+function doFoo($s) {
+	if (preg_match('/(^.+)/', $s, $matches) === 1) {
+		assertType('non-empty-string', $matches[1]);
+	}
+
+	if (preg_match('/(.+$)/', $s, $matches) === 1) {
+		assertType('non-empty-string', $matches[1]);
+	}
+
+	if (preg_match('/(^.+$)/', $s, $matches) === 1) {
+		assertType('non-empty-string', $matches[1]);
+	}
+}