Fix issue 1914 - svn_wc__run_log ignoring external diff3 binary.
Fix issue 1914 - svn_wc__run_log ignoring external diff3 binary.

Use the internal diff3 when running the dry merge to present the
status to the user, and use the user supplied diff3 when running the
real merge.

Patch contributed by Marc Haesen.

* subversion/libsvn_wc/update_editor.c
  (close_directory): Supply the user's diff3 to svn_wc__run_log.
  (install_file): Use the internal diff3.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion