net/http: TestTransportReuseConnEmptyResponseBody

[bcmills]

2020-11-11T14:29:34-c906608/dragonfly-amd64-5_8

--- FAIL: TestTransportReuseConnEmptyResponseBody (0.06s)
    transport_test.go:4287: On request 6, addr "127.0.0.1:57412" != original addr "127.0.0.1:63377"
FAIL
FAIL	net/http	25.950s

I've only seen this failure mode once in the logs, so unclear whether it's a regression or a rare-but-existing flake.

CC @bradfitz @neild @odeke-em

[bcmills]

Two's company. Intriguingly, no overlap in OS or architecture!

greplogs --dashboard -md -l -e 'FAIL: TestTransportReuseConnEmptyResponseBody .*\n .* != original addr ' --since=2020-11-12

2021-12-12T14:36:20-cc795a0/windows-arm64-10