fix(core): remove pending response entries on request timeout and cancellation - #1134
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…cellation McpClientSession and McpServerSession left the pendingResponses entry in place when the downstream timeout fired or the caller cancelled, so each timed-out request leaked its entry forever (request IDs are unique). Mirror the doOnError/doOnCancel cleanup the streamable session variant already performs after .timeout(requestTimeout). Fixes modelcontextprotocol#1133
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Fixes #1133
McpClientSession.sendRequestandMcpServerSession.sendRequestleft theirpendingResponsesentry in place when the downstream.timeout(...)fired or the caller cancelled — the entry was only removed on a response or a send failure. Since request IDs are unique per request, a timed-out request leaked its entry forever;KeepAliveSchedulerpings amplify this into one leaked entry per interval on sessions with a dead peer.Both methods now mirror the cleanup pattern already used by
McpStreamableServerSession.McpStreamableServerSessionStream.sendRequest:doOnError+doOnCancelremove the entry after the timeout boundary. Removal is idempotent, and a late response for a removed id already takes the existing "unexpected response" path.How verified
testRequestTimeoutRemovesPendingResponseinMcpClientSessionTests: a request against a 50 ms-timeout session is let expire, then thependingResponsesmap is asserted empty../mvnw -pl mcp-core testpasses locally.