portfile question concerning optional deps

[Marko Käning]

I am reviving an old thread due to a discussion on http://trac.macports.org/ticket/30206

On Mar 3, 2011, at 11:20 PM, Ryan Schmidt wrote:

>> If you wanted to depend on libsdl.dylib from either libsdl or libsdl-devel, you could use:
>> 
>> lib:libsdl:libsdl
> 
> Do not use bin:- or lib:-style dependencies for this purpose; they would allow a file outside of the MacPorts prefix to satisfy the dependency, and we don't want that. Use only path:-style.

Guide, however, states:

<cite>
File dependencies may be of three types: bin for programs, lib for libraries, and path for any installed file. File dependencies are specifed in the form: <type>:<filespec>:<port>. For bin dependencies, <filespec> is the name of a program in a bin directory like${prefix}/bin. For lib dependencies, <filespec> is the name of a library in a lib directory like ${prefix}/lib but without its extension. For path dependencies, <filespec> is the complete absolute path to the file, or more usually, when the file is inside${prefix}, it is specified relative to ${prefix}.
</cite>

The above doesn't mention that bin: or lib: would actually be satisfied with anything outside prefix. It reads as if it would only below the prefix.

So, what's correct now?