[erlang-patches] Fwd: Re: fixed reading compressed binary terms from Java

Nico Kruber <>
Wed May 9 11:52:18 CEST 2012

forwarded to mailing list as the reply was only send to Henrik Nord...
----------  Forwarded Message  ----------

Subject: Re: [erlang-patches] fixed reading compressed binary terms from Java
Date: Friday 04 May 2012, 16:37:55
From: Nico Kruber <>
To: Henrik Nord <>

Can you give me a hint on how to write and run tests your way?
I could easily write a JUnit test for that and won't even need Erlang since 
the only thing that needs testing here is that write_compressed and read_any 
work with each other with differently sized values. You could even use 
bytes/OtpErlangBinary for simplicity.

The only roundtrip test so far is the echo server, i.e. nc_SUITE.erl, which 
currently only has small terms. I could add larger terms but I need some help 
in how to actually run the test. It is not as simple as "make tests" (with the 
proper ERL_TOP set).


On Friday 27 April 2012 10:23:37 you wrote:
> Hi
> I would like you to add a test for this. As there already are compress
> and decompress roundtrip tests,
> the effort should be minimal for adding tests for this specific bug.
> Also the commit message should conform to
> (fix, not fixed etc..)
> https://github.com/erlang/otp/wiki/Writing-good-commit-messages
> Thank you for the contribution!
> On 04/25/2012 10:48 AM, Nico Kruber wrote:
> > Problem was that when reading from an InputStream, you can only specify a
> > maximum number of bytes to read. Java doesn't guarantee that it actually
> > reads this many bytes - it could be less!
> > 
> > This patch now reads up until the expected size number of bytes. If there
> > are more than expected, the actual number of available bytes is not
> > printed (we probably shouldn't read the additional bytes, security-wise -
> > the erlang external byte representation is broken in this case though).
> > 
> > I applied a patch posted on erlang-questins in September 2009, see
> > http://erlang.org/pipermail/erlang-patches/2009-September/000478.html
> > It was not enough to fix the bug though so I extended this patch a little.
> > 
> > https://github.com/NicoK/otp/compare/jinterface.fix_compressed_binary
> > https://github.com/NicoK/otp/compare/jinterface.fix_compressed_binary.patc
> > h
> > 
> > 
> > Regards
> > Nico Kruber
> > _______________________________________________
> > erlang-patches mailing list
> > 
> > http://erlang.org/mailman/listinfo/erlang-patches

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