added regression test

Author: staabm

src/Type/Php/SprintfFunctionDynamicReturnTypeExtension.php

@@ -7,7 +7,6 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Internal\CombinationsHelper;
-use PHPStan\Php\PhpVersion;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\InitializerExprTypeResolver;
 use PHPStan\TrinaryLogic;

tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php

@@ -1052,4 +1052,10 @@ public function testBug10697(): void
 $this->analyse([__DIR__ . '/data/bug-10697.php'], []);
 }
 
+public function testBug10493(): void
+{
+$this->checkAlwaysTrueStrictComparison = true;
+$this->analyse([__DIR__ . '/data/bug-10493.php'], []);
+}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-10493.php

@@ -0,0 +1,24 @@
+<?php // lint >= 8.1
+
+namespace Bug10493;
+
+class Foo
+{
+public function __construct(
+private readonly ?string $old,
+private readonly ?string $new,
+)
+{
+}
+
+public function foo(): ?string
+{
+$return = sprintf('%s%s', $this->old, $this->new);
+
+if ($return === '') {
+return null;
+}
+
+return $return;
+}
+}