On the pin-externals branch, improve the C test.
On the pin-externals branch, improve the C test.

* subversion/tests/libsvn_client/client-test.c
  (test_copy_pin_externals): Ensure that all externals from test data
   are checked when checking the unparsed form of pinned externals.


git-svn-id: 50c5f5df37af4354ae6e67714fc94b8d09273154@1659370 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion