I saw this happen with updates to my svn working areas after a svn replication problem was fixed on server(wandisco). The svn working areas were inconsistent with svn server (after the change on the server) and had this error which needed fixing. The problem was particular to certain directories (the ones where replication was broken for a time). Probably the svn replication problem fix changed the svn version history, order or svn revision numbers.
How can you identify the directory or files with the problem?
Look at svn status, directory or files with problem status marked with "!" (after you get "Delta source ended unexpectedly" error) are the problem. The dame dirs/files in other working copies probably also have the problem.
How can problem be solved?
Delete the problem directory or files and do svn update.
You may need to repeat this for any dir with problem.
Or do a complete fresh svn checkout.