This is item #7 from Greg Hudson's list of API issues to solve for 1.0, in thread http://subversion.tigris.org/servlets/BrowseList?list=dev&by=thread&from=139821 It says: #7: Overly defensive programming in: svn_path_uri_endode svn_path_uri_decode svn_cstring_split_append The path_uri functions actually document that they will pass through NULL, even though there is no use case which makes that especially convenient. svn_cstring_split_append accepts a NULL input even though it is not documented that it does so. IMPACT OF PROBLEM: Minor; we will be trapped into providing interface guarantees for these functions which we don't provide most places. DIFFICULTY OF FIX: Trivial. Ordinarily we wouldn't need an issue for something so trivial. But since it's an API tweak that probably shouldn't happen in trunk unless it also happens in the 1.0 line, an issue will give us something concrete to refer to in discussions/voting.