[Mapserver-users] httpd-error.log: Incompatible libpng version

[Daniel Morissette]

thelen at ccgis.de wrote:
> 
> gd (I use 2.0.15) does not carry its own internal copy of png.h, but gdal
> does:
> /usr/ports/graphics/gdal/work/gdal-1.1.8/frmts/png/libpng/png.h
> 
> And you are right! This is: libpng version 1.0.6 - March 21, 2000
> 
> So, it is a gdal (and/or a FreeBSD Ports) problem! Isn't "application"
> then in this case gdal??
> 
> 
> What can I do then? 

You need to force GDAL to use the system version of libpng. GDAL has the 
following configure option:

   --with-png[=ARG]        Include PNG support (ARG=internal, no or path)


So you should add "--with-png=/usr/local" to your GDAL configure options 
and rebuild.


> And why does this error not occur with MapServer 3.6.6?
> 

Probably just a coincidence related to the order in which symbols are 
loaded. You definitely have two copies of libpng loaded in memory at 
once in both cases (i.e. in 3.6 and inb 4.0), but in one case the 
problem happens and in the other you're lucky enough that the program 
always uses the right symbols and doesn't produce the error.

Daniel
-- 
------------------------------------------------------------
  Daniel Morissette               morissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/
------------------------------------------------------------