K 10 svn:author V 7 linimon K 8 svn:date V 27 2007-09-30T04:01:39.000000Z K 7 svn:log V 508 Add an anti-foot-shooting measure that protects against a dependent port being null, resulting in an entire category being depended on. This was seen with missing USE_PERL5 definitions, for which there is now a test; however, it could theoretically be tripped over by other bad port Makefiles. Since the failure mode is painful and seems unrelated to the lack of the definition (the build will fail at some random point within that entire category), IMHO it's worth the complexity tradeoff to put this in. END