Index: subversion/libsvn_ra_neon/lock.c
===================================================================
--- subversion/libsvn_ra_neon/lock.c	(revision 1130445)
+++ subversion/libsvn_ra_neon/lock.c	(working copy)
@@ -399,6 +399,7 @@
   const char *url;
   const char *url_path;
   ne_uri uri;
+  svn_error_t *err = SVN_NO_ERROR;
 
   apr_hash_t *extra_headers = apr_hash_make(pool);
 
@@ -441,7 +442,6 @@
 
   {
     int code = 0;
-    svn_error_t *err;
 
     err = svn_ra_neon__simple_request(&code, ras, "UNLOCK", url_path,
                                       extra_headers, NULL, 204, 0, pool);
@@ -460,13 +460,11 @@
                                        _("No lock on path '%s'"
                                          " (%d Bad Request)"), path, code);
             default:
-              break; /* Handle as error */
+              break;
           }
       }
-    else
-      SVN_ERR(err);
   }
-  return SVN_NO_ERROR;
+  return svn_error_return(err);
 }
 
 
Index: subversion/tests/cmdline/lock_tests.py
===================================================================
--- subversion/tests/cmdline/lock_tests.py	(revision 1130445)
+++ subversion/tests/cmdline/lock_tests.py	(working copy)
@@ -1693,6 +1693,33 @@
                                         None, expected_status)
 
 
+#----------------------------------------------------------------------
+def block_unlock_if_pre_unlock_hook_fails(sbox):
+  "block unlock operation if pre-unlock hook fails"
+
+  sbox.build()
+  wc_dir = sbox.wc_dir
+  repo_dir = sbox.repo_dir
+
+  svntest.actions.create_failing_hook(repo_dir, "pre-unlock", "error text")
+
+  # lock a file.
+  pi_path = os.path.join(wc_dir, 'A', 'D', 'G', 'pi')
+  expected_status = svntest.actions.get_virginal_state(wc_dir, 1)
+  expected_status.tweak('A/D/G/pi', writelocked='K')
+
+  svntest.actions.run_and_verify_svn(None, ".*locked by user", [], 'lock',
+                                     '-m', '', pi_path)
+
+  svntest.actions.run_and_verify_status(wc_dir, expected_status)
+
+  # Make sure the unlock operation fails as pre-unlock hook blocks it.
+  expected_unlock_fail_err_re = ".*error text|.*500 Internal Server Error"
+  svntest.actions.run_and_verify_svn2(None, None, expected_unlock_fail_err_re,
+                                      1, 'unlock', pi_path)
+  svntest.actions.run_and_verify_status(wc_dir, expected_status)
+
+
 ########################################################################
 # Run the tests
 
@@ -1739,6 +1766,7 @@
               replace_and_propset_locked_path,
               cp_isnt_ro,
               update_locked_deleted,
+              block_unlock_if_pre_unlock_hook_fails,
             ]
 
 if __name__ == '__main__':