Fix SendRequestAsync hang on Streamable HTTP SSE retry - #1396

Closed

stephentoub with Copilot wants to merge 8 commits into

mainfrom

copilot/replace-corrupted-pr-1381

Commits on Feb 27, 2026

Initial plan
Copilot
committed
1d25d9b
Fix SendRequestAsync hang when background SSE stream delivers response before foreground transport send completes

Copilot
and
stephentoub
committed
3686f6f
Cancel SendToRelatedTransportAsync when response arrives via concurrent channel

Copilot
and
stephentoub
committed
fbf0638
Invert if block for common case, log send faults at debug level

Copilot
and
stephentoub
committed
6a95b4c
Guard send/race block with tcs.Task.IsCompleted check to skip send when response already arrived

Copilot
and
stephentoub
committed
69ed9fb
Simplify ObserveSendFaults: remove #if NET block, inline ContinueWith at call site

Copilot
and
stephentoub
committed
37809ca
Move session ID and background GET setup before SSE processing to prevent cancellation race

Copilot
and
stephentoub
committed
0dea2cc
Fix WhenAny race: await initialize send to completion, only race non-initialize requests

Copilot
and
stephentoub
committed
5dc6598