[Wvware-devel] Re: Png support (PR#647) (fwd)

[Bob F. <bfr...@si...>]

This is what the maintainer of the PNG library (who also assists with
ImageMagick) had to say about the libpng detection issue.  He
recommends testing for png_free.

Bob

---------- Forwarded message ----------
Date: Tue, 06 Feb 2001 07:52:20 -0500
From: Glenn Randers-Pehrson <gl...@ho...>
To: ko...@li...
Subject: Re: Png support (PR#647)

At 01:14 PM 2/6/01 +0200, Giannis Kosmas wrote:
>I am using libpng version 1.0.9. I have installed both the DLL and the
>static version of the library, but the configuration script of
>ImageMagick
>fails...
>
>Is the checking for png_info_init in the configuration script really
>necessary?

The problem is that png_info_init() is not exported.  Not only that,
it is a deprecated function and may be removed from some future version
of libpng.

A better choice to test would be png_free() which has always been in
libpng, always has been exported, and most likely always will be.  It
has always returned without action if it receives NULL parameters.

I just tried that and it worked for me (changed all instances of
png_info_init to png_free in configure and configure.in)

Glenn