Losing the race rejected the caller but did not stop the read. Because
clone() tees the body, a drain still running kept pulling bytes AND
kept buffering them for the unread original branch — unbounded memory
on exactly the signal-ignoring body the race exists to contain.
The clone is now drained through an explicit reader rather than
clone().arrayBuffer(), precisely so the losing side has something it
can cancel: arrayBuffer() locks the stream to an internal reader
nothing else can reach. On any throw both branches are torn down, which
is safe because that path never hands the response to a caller.
The cancels are deliberately not awaited: cancelling one branch of a
tee can itself wait on the other, which would hold the timeout open for
as long as the stall it is meant to end. Each carries its own catch, so
a stream already cancelled, errored or locked elsewhere does not mask
the timeout the caller actually needs — covered by a test whose stream
throws from cancel().
Verified by mutation: removing the teardown makes the new test fail.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YFnM6RqB4nXqNysgUYmjmq
Signed-off-by: cliffhall <cliff@futurescale.com>
78f82475c4