Discrepancy in responding to unacceptable ACK in SYN-RCVD

[zeling]

Description

RFC 793:

SYN-RECEIVED STATE
If SND.UNA =< SEG.ACK =< SND.NXT then enter ESTABLISHED state
and continue processing.
If the segment acknowledgment is not acceptable, form a
reset segment,
              <SEQ=SEG.ACK><CTL=RST>
and send it.

gVisor sends <SEQ=SEG.ACK><ACK=SEG.SEQ+SEG.LEN><CTL=RST,ACK>.

Steps to reproduce

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runsc version

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docker version (if using docker)

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uname

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kubectl (if using Kubernetes)

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repo state (if built from source)

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runsc debug logs (if available)

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