AbortIndex is missing

context.go

@@ -57,6 +57,7 @@ func (a errorMsgs) String() string {
 	}
 	return buffer.String()
 }
+const AbortIndex = math.MaxInt8 / 2
 
 // Context is the most important part of gin. It allows us to pass variables between middleware,
 // manage the flow, validate the JSON of a request and render a JSON response for example.