[SR-16095] SourceKit-LSP server expects a params parameter in the Shutdown request

[adam-fowler]

Previous ID	SR-16095
Radar	rdar://91288093
Original Reporter	@adam-fowler
Type	Bug

Environment

Swift version 5.6 (swift-5.6-RELEASE)
Target: x86_64-unknown-linux-gnu

Additional Detail from JIRA

Votes	0
Component/s	SourceKit-LSP
Labels	Bug
Assignee	None
Priority	Medium

md5: a65d66860c8ab33ed0fd6f1d62c95a20

Issue Description:

SourceKit-LSP server expects a params parameter in the Shutdown request when the spec says it shouldn't include any parameters.

Here is the request/response in the logs

[Trace - 10:19:45] Sending request 'shutdown - (20)'.[Trace - 10:19:45] Received response 'shutdown - (20)' in 2ms. Request failed: missing expected parameter: params (-32602).

This occurs on Linux but not on macOS.

[adam-fowler]

This is caused by SR-16097 where asking for a superDecoder when the fields for that superDecoder do not exist still returns a Decoder on macOS, but on Linux it throws an error

[ahoppen]

Fixed by #474.