Regression test

tests/PHPStan/Analyser/AnalyserIntegrationTest.php

@@ -732,6 +732,15 @@ public function testDiscussion6993(): void
 		$this->assertSame('Parameter #1 $specificable of method Bug6993\AndSpecificationValidator<Bug6993\TestSpecification,Bug6993\Foo>::isSatisfiedBy() expects Bug6993\Foo, Bug6993\Bar given.', $errors[0]->getMessage());
 	}
 
+	public function testBug7077(): void
+	{
+		if (!self::$useStaticReflectionProvider) {
+			$this->markTestSkipped('Test requires static reflection.');
+		}
+		$errors = $this->runAnalyse(__DIR__ . '/data/bug-7077.php');
+		$this->assertNoErrors($errors);
+	}
+
 	/**
 	 * @param string[]|null $allAnalysedFiles
 	 * @return Error[]

tests/PHPStan/Analyser/data/bug-7077.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Bug7077;
+
+function date_add(string $pd, ?int $nr, ?string $date): ?string {
+	if ($date === null || $nr === null) {
+		return null;
+	}
+
+	$interval = new \DateInterval('P' . abs($nr) . $pd);
+
+	$dt = new \DateTime($date);
+	if ($nr >= 0) {
+		$dt->add($interval);
+	} else {
+		$dt->sub($interval);
+	}
+
+	return $dt->format('Y-m-d H:i:s');
+}
+
+function date_add_day(?string $date, ?int $days): ?string {
+	return date_add('D', $days, $date);
+}
+
+function date_add_month(?string $date, ?int $months): ?string {
+	return date_add('M', $months, $date);
+}