Resolve issue #4273, by fixing a filestat in the patch apply code, to stat the
symlink instead of the resolved target.

* trunk/subversion/tests/cmdline/patch_tests.py
  (patch_change_symlink_target): Remove XFail marker.
  
* trunk/subversion/libsvn_client/patch.c
  (init_prop_target,
   get_hunk_info): Use apr_pcalloc to make sure new fields will be set to 0.

  (apply_one_patch): Stat the symlink, not the target to find our result.

  (apply_patches): Use apr_pcalloc to make sure new fields will be set to 0.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1436285 13f79535-47bb-0310-9956-ffa450edef68