bug#4750: 23.1; copied files via dired/tramp/ssh garbled

[Michael Albinus]

Andreas Politz <politza@fh-trier.de> writes:

>>> I open 2 dired buffers, one local, one remote via ssh.  Marking a (any)
>>> file in the local buffer and pressing 'C RET' starts to copy it to the
>>> remote directory.
>>>
>>> Only a part of the file reaches it's destination. Neither dired nor
>>> tramp report any problems. 
>>
>> Could you, please, set `tramp-verbose' to 8, and repeat the test?
>> Afterwards, I would like to see the Tramp debg buffer.
>>
>>> -ap
>>
>> Best regards, Michael.
>
> I copied the 2 shell functions into a script and executed it locally, on
> the remote machine and via `ssh host command'.  No problems there, all
> this methods generate the complete file.
>
> Anyway here is the debug log.

OK, the problem is clear I believe.

> 12:29:01 tramp-send-command (6) # echo \"`uname -sr`\" 2>/dev/null; echo 
> tramp_exit_status $?
> 12:29:01 tramp-wait-for-regexp (6) #
> "AIX 3"
> tramp_exit_status 0
>
> ///643be83973c0506db98f651a756e0efc

Your remote hosts runs AIX. Honestly, this is one of the systems we run
into trouble from time to time ...

> 12:29:44 tramp-send-command (6) # tramp_perl_decode 
> >/u/f0/students/politza/buk.log <<'EOF'
> VGhpcyBpcyBwZGZUZVhrLCBWZXJzaW9uIDMuMTQxNTkyLTEuNDAuMyAoV2ViMkMgNy41LjYpIChm
> b3JtYXQ9cGRmbGF0ZXggMjAwOS4xMC4zKSAgMTggT0NUIDIwMDkgMjA6NTkKZW50ZXJpbmcgZXh0

...

> MDAwIChtYXguIDEwMDAwMDAwKQoK
> EOF

I've taken the whole encoded string from your message, and I've applied
"M-x base64-decode-region" on the region. It decoded fine, to 33024
bytes. But ...

> 12:29:49 tramp-send-command (6) # /usr/bin/ls -d -Al -d buk.log
> 12:29:49 tramp-wait-for-regexp (6) #
> -rwxrwxrwx   1 politza  infstd     26940 Oct 18 18:59 buk.log
>
> ///643be83973c0506db98f651a756e0efc

... there have been copied less bytes.

There is a known bug in `process-send-string'. For some remote systems,
it doesn't send the whole string. You seem to suffer from this.

You might try a workaround, using `tramp-chunksize'. Read the docstring
of that variable, in order to find a way how to set it for your case.

Furthermore, I recommend you to set the variable `file-precious-flag' to
t. In the Tramp case, it adds additional checks, whether a file has been
written correctly.

Best regards, Michael.