Subject: Re: SFTP issues

Re: SFTP issues

From: Peter Stuge <>
Date: Thu, 2 Feb 2012 13:03:40 +0100

Hi Alex,

Alexander Lamaison wrote:
> SFTP reading is completely broken for me in 1.4.0 (though it has been
> for a while). The last release that works for me is 1.2.7.

Bad. We need to fix this.

> Some revisions cause a read with a buffer larger than 65-130k to
> block. Other revisions cause reads to return 0 prematurely indicating
> the end of the file (usually around the 200k mark). Recent revisions
> do the latter.
> Using my usual test script (attached) and git bisect I've narrowed
> down the offending commits. Apparently, premature EOF is caused by
> 03ca9020756a4e16f0294e5b35e9826ee6af2364 [1] and blocking is caused by
> 90b4b4073f34919aa72deff61a5c9bc188c47c95 [2]. It's difficult to know
> how accurate these are as there were several overlapping, interacting
> bugs and attempts to fix them that kept changing the SFTP behaviour.
> This is all on Windows 7 64-bit. To try the script yourself, run it as:
> libssh2_bigread ip_address username password path
> If you run it with something like /dev/zero as the path, the expected
> behaviour is that it will try reading from that path with increasing
> buffer sizes up to about 8MB.
> Daniel, liuzl: we went through this process in September and you guys
> made some fixes which I though had solved it. I've changed both the
> Windows and Linux machines I'm testing on since then so I don't know
> if that's why the problems are back. I don't understand enough about
> the SFTP layer to suggest a fix but, as usual, I'll happily test any
> patches.

Could you test if this happens also from Linux to Linux? Would be
good to test both on localhost on the server where Windows 7 shows
this problem, and between two different Linux machines.

Could you stop by IRC soonish for some more discussion and testing?

Received on 2012-02-02