Address review on PR 9424:
* coderabbit (HIGH, line 122): ReadUrlAsStream can set shouldRetry=true
with readErr=nil. Before this fix, that fell through to mw.Close()
and the destination POST succeeded against a possibly-truncated
multipart body. Mirror downloadChunkData's explicit check and
surface shouldRetry as a producer error so the dst POST aborts.
* gemini (line 98): chunk size is int64 but ReadUrlAsStream takes int.
Reject sizes above MaxInt32 up front so the int(size) cast can't
truncate negative on 32-bit platforms — same guard downloadChunkData
uses.
* gemini (line 151): util_http.CloseResponse already drains the body
(io.Copy(io.Discard, ...) inside the helper) before closing, so the
manual io.Copy drains we added are redundant. Drop them.
Chris Lu
f70f338e7f