Extract auto-index condition into private method and handle PHP 8.0+ array literal behavior

PHP 8.0 changed array literals to update the auto-increment key for
negative values, while imperative assignment only got this fix in PHP 8.3.
Extract the condition into shouldUpdateAutoIndexForOffset() for readability
and add isLiteralArray flag to ConstantArrayTypeBuilder to distinguish the
two cases.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

src/Php/PhpVersion.php

@@ -516,4 +516,9 @@ public function updatesAutoIncrementKeyForNegativeValues(): bool
 		return $this->versionId >= 80300;
 	}
 
+	public function updatesAutoIncrementKeyForNegativeValuesInArrayLiteral(): bool
+	{
+		return $this->versionId >= 80000;
+	}
+
 }

src/Reflection/InitializerExprTypeResolver.php

@@ -639,6 +639,7 @@ public function getArrayType(Expr\Array_ $expr, callable $getTypeCallback): Type
 		}
 
 		$arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
+		$arrayBuilder->setLiteralArray();
 		$isList = null;
 		$hasOffsetValueTypes = [];
 		foreach ($expr->items as $arrayItem) {

src/Type/Constant/ConstantArrayTypeBuilder.php

@@ -42,6 +42,8 @@ final class ConstantArrayTypeBuilder
 
 	private bool $oversized = false;
 
+	private bool $isLiteralArray = false;
+
 	/**
 	 * @param list<Type> $keyTypes
 	 * @param array<int, Type> $valueTypes
@@ -63,6 +65,11 @@ public static function createEmpty(): self
 		return new self([], [], [0], [], TrinaryLogic::createYes());
 	}
 
+	public function setLiteralArray(): void
+	{
+		$this->isLiteralArray = true;
+	}
+
 	public static function createFromConstantArray(ConstantArrayType $startArrayType): self
 	{
 		$builder = new self(
@@ -426,7 +433,17 @@ private function shouldUpdateAutoIndex(int $offsetValue, int $max): bool
 			return true;
 		}
 
-		return $offsetValue < 0 && $max === 0 && PhpVersionStaticAccessor::getInstance()->updatesAutoIncrementKeyForNegativeValues();
+		if ($offsetValue >= 0 || $max !== 0) {
+			return false;
+		}
+
+		$phpVersion = PhpVersionStaticAccessor::getInstance();
+
+		if ($phpVersion->updatesAutoIncrementKeyForNegativeValues()) {
+			return true;
+		}
+
+		return $this->isLiteralArray && $phpVersion->updatesAutoIncrementKeyForNegativeValuesInArrayLiteral();
 	}
 
 }