**GWT version: 2.8.1

**Browser (with version): Chrome Version 59.0.3071.115 (Official Build) (64-bit)

**Operating System: Arch Linux 4.11.9-1-ARCH

Description

We ran into a corner case bug with the GWT RPC deserialisation process. The code in question uses GWT portlets. ServerSerializationStreamWriter defines MAXIMUM_ARRAY_LENGTH = 1 << 15.

When the response payload exceeds MAXIMUM_ARRAY_LENGTH by 1, the payload looks something like //OK["random data", 1,2,3,...,0].concat([7]). The response is returned to the client successfully, however when the client tries deserialising this payload it throws a NumberFormatException for input string "0].concat([7". See the stackstrace below. For arrays bigger than MAXIMUM_ARRAY_LENGTH + 1 it successfully deserialises.

 java.lang.NumberFormatException: For input string: "0].concat([7" Unknown.ec(Throwable.java:67) Unknown.Hc(Exception.java:29) Unknown.uo(RuntimeException.java:29) Unknown.rBe(IllegalArgumentException.java:29) Unknown.$Ce(NumberFormatException.java:41) Unknown._Ce(NumberFormatException.java:26) Unknown.oye(Number.java:222) Unknown.NBe(Integer.java:157) Unknown.MBe(Integer.java:153) Unknown.fDd(ClientSerializationStreamReader.java:148) Unknown.WCd(ClientSerializationStreamReader.java:61) Unknown.DDd(RemoteServiceProxy.java:259) Unknown._Dd(RequestCallbackAdapter.java:214) Unknown.MPi(SidRpcRequestBuilder.java:60) Unknown.eQ(Request.java:250) Unknown.UQ(RequestBuilder.java:412) Unknown.anonymous(XMLHttpRequest.java:329) Unknown.Gr(Impl.java:239) Unknown.Jr(Impl.java:291) Unknown.anonymous(Impl.java:77) 

Steps to reproduce

This is difficult to reproduce in a open source demo given that I don't know how to deterministically produce a payload with an array of a specific length, as the serialisation process is not straightforward. Possibly someone that understands the gwt serialisation can give some input here.