For some reason there is some bad information out there on comparing a local working copy in a branch to that of a subversion url. In this case, I really wanted to know how far off this branch code that wasn’t commited is from the trunk. To do that, you just need to use the ‘–old’ and ‘–new’ flags.
$ cd ./branches/one $ svn diff --old=svn://server/Project/trunk --new=. > working.diff
Then all that needs to be done to update a branch of trunk to that is:
$ patch -p0 -i workingdiff.diff