Branching directories with fully-contained externals with svncopy.pl

I have found a bug in the svncopy.pl script that fails to properly
handle fully-contained externals when branching and copying from a
single source. When branching from a single source, the externals are
updated to directories that do not exist.

Taken from the README
<http://svn.apache.org/repos/asf/subversion/trunk/contrib/client-side/svncopy/svncopy.README>,
example 5 "branching properly"...

---
Using the script allows branches to be created which are really independent.
$ perl svncopy.pl --branch http://svn/repos/trunk \
             http://svn/repos/branches/3.2_bugfix
Result:
trunk/
     [ as above]
branches/
     3.2_bugfix/
         trunk/
             common/
                 common1.c
                 common2.c
             inc/
                 common1.h
                 common2.h
             proj_foo/
                 foo1.c
                 foo2.c
                 X common    -r 4997 http://svn/repos/trunk/common
                 X inc       http://svn/repos/branches/3.2_bugfix/trunk/inc
[rest of example tree omitted]
---
The current svncopy.pl script has special logic for a single source and 
no longer creates the branches/3.2_bugfix/trunk directory, but puts the 
contents directly in branches/3.2_bugfix.  The logic is more along the 
lines of the "svn copy" command.  (This was added in a patch a year ago. 
  <http://svn.haxx.se/dev/archive-2009-06/0064.shtml>)
The problem is the fully-contained external, when updated for the 
branch, is still updated to what the non-patched version would have 
created, http://svn/repos/branches/3.2_bugfix/trunk/inc, which no longer 
exists.
I can try to fix it, but I have very little Perl experience, and 
definitely not enough to easily understand the testsvncopy.pl script to 
make a test case.
Here is the verbose output of a branch command up until the error first 
appears.
$ svncopy.pl -b --verbose 
https://192.168.1.197/svn/ASA/branches/release/trunk-v01_00b2/trunk 
https://192.168.1.197/svn/ASA/Sandbox/AF/tmp/branch_test
=================================================================
=== Copying from:
=== 
https://192.168.1.197/svn/ASA/branches/release/trunk-v01_00b2/trunk
===
=== Copying to:
===       https://192.168.1.197/svn/ASA/Sandbox/AF/tmp/branch_test
===
===  - branching (updating fully-contained svn:externals definitions)
===
multiple_sources: No
Using temporary directory /tmp/svncopy_S1AkIqIak9
Copying source URI to destination URI
  > svn copy --file /tmp/svncopy_S1AkIqIak9/CDYv8LFfbX 
https://192.168.1.197/svn/ASA/branches/release/trunk-v01_00b2/trunk 
https://192.168.1.197/svn/ASA/Sandbox/AF/tmp/branch_test
Checking out destination directory '/tmp/svncopy_S1AkIqIak9/branch_test'
  > svn co https://192.168.1.197/svn/ASA/Sandbox/AF/tmp/branch_test 
/tmp/svncopy_S1AkIqIak9/branch_test
Checking '/tmp/svncopy_S1AkIqIak9/branch_test'
  > svn propget -R svn:externals /tmp/svncopy_S1AkIqIak9/branch_test
  - Found c-SimpleReturns => 
'https://192.168.1.197/svn/ASA/branches/release/trunk-v01_00b2/trunk/projects/barring/toolkit-simple-returns/c-SimpleReturns'
  - updated 'c-SimpleReturns 
https://192.168.1.197/svn/ASA/branches/release/trunk-v01_00b2/trunk/projects/barring/toolkit-simple-returns/c-SimpleReturns' 
to 'c-SimpleReturns 
https://192.168.1.197/svn/ASA/Sandbox/AF/tmp/branch_test/trunk/projects/barring/toolkit-simple-returns/c-SimpleReturns'
[rest omitted]
Again, note that although the branch is at branch_test, the new external 
points to branch_test/trunk.
-- 
Anthony Foglia
Princeton Consultants
(609) 987-8787 x233