Correctly restoring channel's FDs nonblocking mode#246
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OpenSSH incorrectly restores the standard mode (blocking mode) on standard output upon exiting. This causes the next shell scripts commands to potentially fail in EAGAIN.
The reproducer is:
#!/bin/sh
(
ssh localhost true
cat /dev/zero
) | sleep 30
Restoring the blocking modes happens with the duped file descriptors and too late.
The changes causing this problem was introduced in 4d5456c
The previous patches was provided in #244
This is an alternate approach to fix this problem provided by Masaki Kimura