fix(mcp): guard nil initializeParams on id:null with new-protocol _meta#1048
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fix(mcp): guard nil initializeParams on id:null with new-protocol _meta#1048kuangmi-bit wants to merge 1 commit into
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When a request carries id:null (IsCall() returns false), validateRequestMeta returns initializeParams=nil but usesNewProtocol=true. The subsequent protocol-version check dereferences the nil pointer, causing SIGSEGV. Add a nil guard matching the pattern already used at the initialization check (line 1846). Regression test exercises completion/complete, prompts/get, and tools/call with id:null + new-protocol _meta — all three previously panicked before the fix. Fixes modelcontextprotocol#1043
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Problem
When an inbound JSON-RPC frame carries
"id": nullwith per-request_metafor protocol version2026-07-28, the server panics with SIGSEGV (nil pointer dereference oninitializeParams.ProtocolVersion).The root cause is a two-step gap:
validateRequestMetareturnsinitializeParams: nil, usesNewProtocol: truewhenreq.IsCall()returns false (triggered byid: null).ServerSession.handledereferencesinitializeParams.ProtocolVersionwithout checking for nil.Fixes: #1043
Fix
One-line nil guard at
server.go:1815, matching the pattern already used on line 1846:Test
Regression test exercises three methods (
completion/complete,prompts/get,tools/call) withid: null+ new-protocol_meta— all three previously panicked, now return gracefully.