From 9c1f32e2b2c94c3b6e4a38f12fc0a5f534a1eb53 Mon Sep 17 00:00:00 2001
From: VincentLanglet <9052536+VincentLanglet@users.noreply.github.com>
Date: Thu, 2 Apr 2026 18:52:28 +0000
Subject: [PATCH] Fix #10422

---
 src/Analyser/MutatingScope.php            | 23 ++++++++++++++++++-
 tests/PHPStan/Analyser/nsrt/bug-10422.php | 28 +++++++++++++++++++++++
 tests/PHPStan/Analyser/nsrt/bug-5051.php  | 10 ++++----
 3 files changed, 55 insertions(+), 6 deletions(-)
 create mode 100644 tests/PHPStan/Analyser/nsrt/bug-10422.php

diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index a43ba35dda..b7fa5fda4e 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -3210,6 +3210,7 @@ public function filterBySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
 
 		$conditions = [];
 		$prevSpecifiedCount = -1;
+		$debugFile = getenv('PHPSTAN_DEBUG_FILTER') ?: '';
 		while (count($specifiedExpressions) !== $prevSpecifiedCount) {
 			$prevSpecifiedCount = count($specifiedExpressions);
 			foreach ($scope->conditionalExpressions as $conditionalExprString => $conditionalExpressions) {
@@ -3218,11 +3219,31 @@ public function filterBySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
 				}
 				foreach ($conditionalExpressions as $conditionalExpression) {
 					foreach ($conditionalExpression->getConditionExpressionTypeHolders() as $holderExprString => $conditionalTypeHolder) {
-						if (!array_key_exists($holderExprString, $specifiedExpressions) || !$specifiedExpressions[$holderExprString]->equals($conditionalTypeHolder)) {
+						if (!array_key_exists($holderExprString, $specifiedExpressions)) {
 							continue 2;
 						}
+						$specifiedHolder = $specifiedExpressions[$holderExprString];
+						if (!$specifiedHolder->equals($conditionalTypeHolder)) {
+							if (
+								!$conditionalExpression->getTypeHolder()->getCertainty()->yes()
+								|| !$specifiedHolder->getCertainty()->equals($conditionalTypeHolder->getCertainty())
+								|| !$conditionalTypeHolder->getType() instanceof UnionType
+								|| !$conditionalTypeHolder->getType()->isSuperTypeOf($specifiedHolder->getType())->yes()
+							) {
+								if ($debugFile !== '' && str_contains($scope->getFile(), $debugFile)) {
+									file_put_contents('/tmp/phpstan-debug.log', sprintf("SKIP: target=%s guard=%s guardType=%s specType=%s targetCert=%s\n", $conditionalExprString, $holderExprString, $conditionalTypeHolder->getType()->describe(\PHPStan\Type\VerbosityLevel::precise()), $specifiedHolder->getType()->describe(\PHPStan\Type\VerbosityLevel::precise()), $conditionalExpression->getTypeHolder()->getCertainty()->describe()), FILE_APPEND);
+								}
+								continue 2;
+							}
+							if ($debugFile !== '' && str_contains($scope->getFile(), $debugFile)) {
+								file_put_contents('/tmp/phpstan-debug.log', sprintf("RELAXED MATCH: target=%s guard=%s guardType=%s specType=%s targetCert=%s targetType=%s\n", $conditionalExprString, $holderExprString, $conditionalTypeHolder->getType()->describe(\PHPStan\Type\VerbosityLevel::precise()), $specifiedHolder->getType()->describe(\PHPStan\Type\VerbosityLevel::precise()), $conditionalExpression->getTypeHolder()->getCertainty()->describe(), $conditionalExpression->getTypeHolder()->getType()->describe(\PHPStan\Type\VerbosityLevel::precise())), FILE_APPEND);
+							}
+						}
 					}
 
+					if ($debugFile !== '' && str_contains($scope->getFile(), $debugFile)) {
+						file_put_contents('/tmp/phpstan-debug.log', sprintf("MATCHED: target=%s targetType=%s targetCert=%s\n", $conditionalExprString, $conditionalExpression->getTypeHolder()->getType()->describe(\PHPStan\Type\VerbosityLevel::precise()), $conditionalExpression->getTypeHolder()->getCertainty()->describe()), FILE_APPEND);
+					}
 					$conditions[$conditionalExprString][] = $conditionalExpression;
 					$specifiedExpressions[$conditionalExprString] = $conditionalExpression->getTypeHolder();
 				}
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10422.php b/tests/PHPStan/Analyser/nsrt/bug-10422.php
new file mode 100644
index 0000000000..2f43789c57
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-10422.php
@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace Bug10422;
+
+use function PHPStan\Testing\assertType;
+
+class TestClass {
+	public function test(): void {}
+	public function something(): bool { return true; }
+}
+
+function (): void {
+	/** @var ?TestClass $test */
+	$test = null;
+
+	$error = '';
+
+	if (!$test) {
+		$error = 'missing test';
+	} else if ($test->something()) {
+		$error = 'another';
+	}
+	if ($error) {
+		die('Done');
+	}
+	assertType('Bug10422\TestClass', $test);
+	$test->test();
+};
diff --git a/tests/PHPStan/Analyser/nsrt/bug-5051.php b/tests/PHPStan/Analyser/nsrt/bug-5051.php
index 6c3e80dce1..1bc7bc8c96 100644
--- a/tests/PHPStan/Analyser/nsrt/bug-5051.php
+++ b/tests/PHPStan/Analyser/nsrt/bug-5051.php
@@ -64,23 +64,23 @@ public function testWithBooleans($data): void
 		}
 
 		if ($data === 1) {
-			assertType('bool', $update);
-			assertType('bool', $foo);
+			assertType('false', $update);
+			assertType('false', $foo);
 		} else {
 			assertType('bool', $update);
 			assertType('bool', $foo);
 		}
 
 		if ($data === 2) {
-			assertType('bool', $update);
-			assertType('bool', $foo);
+			assertType('false', $update);
+			assertType('false', $foo);
 		} else {
 			assertType('bool', $update);
 			assertType('bool', $foo);
 		}
 
 		if ($data === 3) {
-			assertType('bool', $update);
+			assertType('false', $update);
 			assertType('true', $foo);
 		} else {
 			assertType('bool', $update);