I always think that using SVN is like using a really broken version of git. The fact that SVN allows you to checkout part of a tree and thus have any folder as the root of your source controller encourages developers to hack solutions which is probably why they had to invent the idea of keeping track of and committing individual revisions rather than encouraging developers to bring a branch up to date. A lot of people say they don't like Clearcase because you can make a config spec that gives you a view where it shows folders from different parts of your history or from different branches. The difference is that Clearcase gives you loads of great tools to help manage it all where as SVN gives you practically nothing - the easiest way to manage SVN merging is still finding all the revision numbers and writing them down on a piece of paper and merging them individually, on a big project this can take weeks.
As a result I try not to waste my brain space on things that aren't worth remembering so this is the place for all those SVN related commands that I need from time to time.
Find the revision the branch was taken from
svn log --stop-on-copy
More information can be found here: Getting svn to ignore files and directories