Looking in Plugins Trac > trunk I notice that the svn:ignore property includes vendor. The same seems true of all the existing branches.

Not 100% sure, but I think if you remove vendor from that prop, then the vendor dir will get committed to SVN, which should solve the recent problems.
Looking in Plugins Trac > trunk I notice that the
svn:ignoreproperty includesvendor. The same seems true of all the existing branches.Not 100% sure, but I think if you remove
vendorfrom that prop, then thevendordir will get committed to SVN, which should solve the recent problems.