don't crash on negative multiplier

phpstan · Feb 22, 2022 · e3df0c3 · e3df0c3
1 parent 954e089
commit e3df0c3
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Showing 2 changed files with 7 additions and 0 deletions.
diff --git a/src/Type/Php/StrRepeatFunctionReturnTypeExtension.php b/src/Type/Php/StrRepeatFunctionReturnTypeExtension.php
@@ -12,9 +12,11 @@
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntersectionType;
+use PHPStan\Type\NeverType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
 use function count;
+use function str_repeat;
 
 class StrRepeatFunctionReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
@@ -42,6 +44,10 @@ public function getTypeFromFunctionCall(
 			return new ConstantStringType('');
 		}
 
+		if ($multiplierType instanceof ConstantIntegerType && $multiplierType->getValue() < 0) {
+			return new NeverType();
+		}
+
 		if ($inputType instanceof ConstantStringType && $multiplierType instanceof ConstantIntegerType) {
 			return new ConstantStringType(str_repeat($inputType->getValue(), $multiplierType->getValue()));
 		}

diff --git a/tests/PHPStan/Analyser/data/literal-string.php b/tests/PHPStan/Analyser/data/literal-string.php
@@ -28,6 +28,7 @@ public function doFoo($literalString, string $string)
 		assertType("''", str_repeat('', 10));
 		assertType("'foofoofoofoofoofoofoofoofoofoo'", str_repeat('foo', 10));
 		assertType("'?,?,?,'", str_repeat('?,', 3));
+		assertType("*NEVER*", str_repeat('?,', -3));
 
 		assertType('non-empty-string', str_pad($string, 5, $string));
 		assertType('non-empty-string', str_pad($literalString, 5, $string));