finding png libraries in configure scripts

[Brook Milligan <brook%nmsu.edu@localhost>]

I am working on a package that uses png but the configure script tries to find libpng.so not libpng16.so.  Note that it does this by looking for the file directly not linking.

This more or less falls into the situation described below from png/buildlink3.mk.

# Some software directly tries to link against -lpng instead of                 
# using pkg-config or libpng-config to find the proper arguments                
# instead of installing symlinks. Work around this with buildlink               
# magic: packages outside pkgsrc will need to be converted to                   
# one of the proper methods or fail.                                            
BUILDLINK_TRANSFORM+=   l:png:png16

However, transforms for link commands will not fix the direct file lookup.  

What is the best way to handle this.

- Patch configure to look for libpng16.so?

- Use SUBST stuff and a magic make variable for the png version in the package?

- Use something like Makefile.version in the png package to define a magic make variable for cases like this?

- Other ideas?

Is this a problem for other packages or does the buildlink transform capture everything else?

Thanks for help.

Cheers,
Brook