Add an FsPutRetry integration test which uses the fshttp fault injector
to fail the first request carrying upload data, before it is sent, with
either a synthetic 500 or a connection reset, and then checks that Put
either succeeds with the correct contents or fails cleanly without
leaving a corrupt object behind.
It runs a single part upload and, for backends implementing
SetUploadChunkSizer, a chunked one. This catches backends which retry
an upload from a buffer which has already been consumed or returned to
the memory pool. Backends which don't use HTTP skip the test.
Also check in FsPutRetry and the large upload tests that the number of
buffers in use in the global memory pool is unchanged after an upload,
to catch backends which leak pooled buffers.
Nick Craig-Wood
05ac69e123