Re: gnuplot-4.0.0 fails to link on Digital UNIX V4.0E

[Hans-Bernhard B. <br...@ph...>]

On Sun, 25 Apr 2004, Ethan Merritt wrote:

> On Sunday 25 April 2004 12:56 pm, Hans-Bernhard Broeker wrote:
[...]
> > That's not the right way of fixing this, of course.  The actual
> > bug is in configure.in, where linking against -lgd and -lpng is
> > tested and the variables used in the link command are set up.
> >
> > Ethan: I'm CCing you on this because if memory serves, it was you who
> > claimed that the tests in their current shape are the only way to get
> > this to work on some platforms.  
> 
> I have vague recollections of saying that, but the only thing I can
> find in the mailing list archive (from Jan 2003) is a slightly 
> different issue. I was making the point that (at least under linux) 
> if ./configure tests for libpng and finds it, it will be finding the 
> most current installed version.  But this version may not
> match the one that, say, libgd was linked against.  In this case you get
> incompatibility warnings at link time.  So I was arguing against 
> specifying "-lpng -lz" explicitly if libgd was already being included.

And that argument, as far as I can recall, is the exact reason why -lz is
not currently appended to the link command line by the -lgd tests.  This
approach broke on at least 3 platforms by current count.  In fact, it'll
break all platforms with static libraries and those with shared libraries,
but without inter-library dependency support.

> Regardless of all that, the current report looks to me to be a different
> issue.  He had to change the order of the libraries in the link statement.
> Apparently ./configure places them in the wrong order.

> If I ever had a reason for wanting -lz to come before -lpng I can no longer
> remember what it might have been.  So if moving the tests on libz to after
> the png tests fixes the problem, I have no objection (but we should test
> it first, of course).

That cannot possibly work, I think.  We have to test for -lz first, then,
if that exists, use it in the -lpng and -lgd link tests.  

-- 
Hans-Bernhard Broeker (br...@ph...)
Even if all the snow were burnt, ashes would remain.