Ease your vendor branch management worries with Piston, a tool to copy vendor / upstream code to your own repository, while preserving your local patches.
Use the convert subcommand if you have a Subversion working copy in which you have svn:externals references. This command will convert each of the svn:externals references running import on each of them.
SYNOPSIS
piston convert [directories*] [options]+
PARAMETERS
directories (-1 ~> directories)
Which directory/directories to convert from svn:externals to Piston.
Not specifying this argument recursively converts the whole directory
tree starting from the current dir.
--verbose=[verbose], -v (0 ~> integer(verbose=0))
Verbosity level (0 to 5, 0 being the default)
--quiet, -q
--force
--dry-run
--help, -h