Mercurial in pure Java

[Theodore Tso]

On Thu, Oct 01, 2009 at 07:50:40AM +0200, Alexander Schatten wrote:
> 
> Yes, but I think there is a misunderstanding here: the question is
> not what you ship together, but what is linked together.
> 
> If the judge asks you, if you can remove the JRE and Linux is still
> working (except for Java programs) you can say yes; if he asks you
> if you can put the JRE to a different Linux distribution and Java
> programs are still working, you can also answer "yes".
> 
> But if he asks you, if you can remove Mercurial and the Mercurial
> Eclipse plugin is still working, the answer is clearly "No". The
> Plugin only works with Mercurial. Not with GIT, not with
> Bazaar. Insofar it is pretty hard linked. And that is imho a
> significant issue that makes the plugin derivative work.

This is not at all correct.  The question is whether something is a
derived work or not.  Copyright licenses get their power from
copyright law, and so at the end of the day, it is not a matter of
whether one program is dependent on another, but a matter of copyright
law, and what it means for something to be a derived work.  

By your reasoning, a shell script which runs a GPL'ed program, or a C
program which runs a GPL'ed program using the system(3) library
function, must be under the GPL since the shell script or the C
program wouldn't function if the GPL'ed program exists.  This is of
course nonsense.  Proprietary programs can run GPL'ed programs without
getting infected by the GPL license.  This has been well established
for a long, LONG time.

If you don't believe me, ask the FSF or the SFLC.  But please don't
make authoratative statements about copyright law, or attempt to give
legal advice, when you are clearly clueless about such matters.

					- Ted