I\'m using Subversion 1.5 and have a single file in a branch that I want to merge into another branch. When I do a svn merge http://path/to/file
I get an error,
Im am using subversion 1.8.8 and
svn merge ^/trunk/path_to_file ./branch/path_to_local_file
works fine for me.
I think you need to do a
svn merge http://server/repos/path/to -r <REV>
where <REV> is the revision where the file was added. That way merge information is recorded (in case of a Subversion 1.5 or higher repository).
Try specifying the path to the local file as well.
For example,
svn merge -r1234:1235 svn://your_svn_url/to/file ./local_file
The merge, as Andrew recommended it, worked for me, but not for every file. I had three files, but for the third I got the error "...path not found". Adding the argument " --ignore-ancestry" solved that problem.
But after merging I had strange modified/merged file status and a lot of svn:mergeinfo
added to my working copy.
So I decided to just do a simple copy&paste for single files to avoid such confusing stuff until we switch to Git where these tasks are really no problem at all ;)
I think your best best is an svn copy from one branch to the other.