Index: subversion/tests/cmdline/basic_tests.py
===================================================================
--- subversion/tests/cmdline/basic_tests.py	(revision 25134)
+++ subversion/tests/cmdline/basic_tests.py	(working copy)
@@ -1935,8 +1935,164 @@
                                         expected_output,
                                         expected_disk,
                                         expected_status)
+  
+#----------------------------------------------------------------------
 
+def automatic_conflict_resolution(sbox):
+  "automatic conflict resolution"
 
+  sbox.build()
+  wc_dir = sbox.wc_dir
+
+  # Make a backup copy of the working copy
+  wc_backup = sbox.add_wc_path('backup')
+  svntest.actions.duplicate_dir(wc_dir, wc_backup)
+
+  # Make a couple of local mods to files which will be committed
+  mu_path = os.path.join(wc_dir, 'A', 'mu')
+  lambda_path = os.path.join(wc_dir, 'A', 'B', 'lambda')
+  rho_path = os.path.join(wc_dir, 'A', 'D', 'G', 'rho')
+  svntest.main.file_append(mu_path, 'Original appended text for mu\n')
+  svntest.main.file_append(lambda_path, 'Original appended text for lambda\n')
+  svntest.main.file_append(rho_path, 'Original appended text for rho\n')
+
+  # Make a couple of local mods to files which will be conflicted
+  mu_path_backup = os.path.join(wc_backup, 'A', 'mu')
+  lambda_path_backup = os.path.join(wc_backup, 'A', 'B', 'lambda')
+  rho_path_backup = os.path.join(wc_backup, 'A', 'D', 'G', 'rho')
+  svntest.main.file_append(mu_path_backup,
+                             'Conflicting appended text for mu\n')
+  svntest.main.file_append(lambda_path_backup,
+                             'Conflicting appended text for lambda\n')
+  svntest.main.file_append(rho_path_backup,
+                             'Conflicting appended text for rho\n')
+
+  # Created expected output tree for 'svn ci'
+  expected_output = wc.State(wc_dir, {
+    'A/mu' : Item(verb='Sending'),
+    'A/B/lambda' : Item(verb='Sending'),
+    'A/D/G/rho' : Item(verb='Sending'),
+    })
+
+  # Create expected status tree; all local revisions should be at 1,
+  # but lambda, mu and rho should be at revision 2.
+  expected_status = svntest.actions.get_virginal_state(wc_dir, 1)
+  expected_status.tweak('A/mu', 'A/B/lambda', 'A/D/G/rho', wc_rev=2)
+
+  # Commit.
+  svntest.actions.run_and_verify_commit(wc_dir, expected_output,
+                                        expected_status, None,
+                                        None, None, None, None, wc_dir)
+
+  # Create expected output tree for an update of the wc_backup.
+  expected_output = wc.State(wc_backup, {
+    'A/mu' : Item(status='C '),
+    'A/B/lambda' : Item(status='C '),
+    'A/D/G/rho' : Item(status='C '),
+    })
+  
+  # Create expected disk tree for the update.
+  expected_disk = svntest.main.greek_state.copy()
+  expected_disk.tweak('A/mu', contents="""This is the file 'mu'.
+<<<<<<< .mine
+Conflicting appended text for mu
+=======
+Original appended text for mu
+>>>>>>> .r2
+""")
+  expected_disk.tweak('A/B/lambda', contents="""This is the file 'lambda'.
+<<<<<<< .mine
+Conflicting appended text for lambda
+=======
+Original appended text for lambda
+>>>>>>> .r2
+""")
+  expected_disk.tweak('A/D/G/rho', contents="""This is the file 'rho'.
+<<<<<<< .mine
+Conflicting appended text for rho
+=======
+Original appended text for rho
+>>>>>>> .r2
+""")
+
+  # Create expected status tree for the update.
+  expected_status = svntest.actions.get_virginal_state(wc_backup, '2')
+  expected_status.tweak('A/mu', 'A/B/lambda', 'A/D/G/rho', status='C ')
+
+  # "Extra" files that we expect to result from the conflicts.
+  # These are expressed as list of regexps.  What a cool system!  :-)
+  extra_files = ['mu.*\.r1', 'mu.*\.r2', 'mu.*\.mine',
+                 'lambda.*\.r1', 'lambda.*\.r2', 'lambda.*\.mine',
+                 'rho.*\.r1', 'rho.*\.r2', 'rho.*\.mine',]
+  
+  # Do the update and check the results in three ways.
+  # All "extra" files are passed to detect_conflict_files().
+  svntest.actions.run_and_verify_update(wc_backup,
+                                        expected_output,
+                                        expected_disk,
+                                        expected_status,
+                                        None,
+                                        svntest.tree.detect_conflict_files,
+                                        extra_files)
+  
+  # verify that the extra_files list is now empty.
+  if len(extra_files) != 0:
+    # Because we want to be a well-behaved test, we silently raise if
+    # the test fails.  However, these two print statements would
+    # probably reveal the cause for the failure, if they were
+    # uncommented:
+    #
+    # print "Not all extra reject files have been accounted for:"
+    # print extra_files
+    ### we should raise a less generic error here. which?
+    raise svntest.Failure
+
+  # So now lambda, mu and rho are all in a "conflicted" state.  Run 'svn
+  # resolved' with the respective "--accept[mine|orig|repo]" flag.
+
+  # Run 'svn resolved --accept=orig.  Using lambda for the test.
+  svntest.actions.run_and_verify_svn("Resolved command", None, [],
+                                     'resolved',
+                                     '--accept=orig',
+                                     lambda_path_backup)
+
+  # Run 'svn resolved --accept=mine.  Using mu for the test.
+  svntest.actions.run_and_verify_svn("Resolved command", None, [],
+                                     'resolved',
+                                     '--accept=mine',
+                                     mu_path_backup)
+
+  # Run 'svn resolved --accept=repo.  Using rho for the test.
+  svntest.actions.run_and_verify_svn("Resolved command", None, [],
+                                     'resolved',
+                                     '--accept=repo',
+                                     rho_path_backup)
+  
+  # Set the expected disk contents for the test
+  expected_disk = svntest.main.greek_state.copy()
+  
+  expected_disk.tweak('A/B/lambda', contents="This is the file 'lambda'.\n")
+  expected_disk.tweak('A/mu', contents="This is the file 'mu'.\n"
+                      "Conflicting appended text for mu\n")
+  expected_disk.tweak('A/D/G/rho', contents="This is the file 'rho'.\n"
+                      "Original appended text for rho\n")
+
+  # Set the expected status for the test
+  expected_status = svntest.actions.get_virginal_state(wc_backup, '2')
+  
+  expected_status.tweak('A/mu', status='M ')
+  expected_status.tweak('A/B/lambda', status='M ')
+  expected_status.tweak('A/D/G/rho', status='  ')
+
+  # Do the update and check the results in three ways.
+  svntest.actions.run_and_verify_update(wc_backup,
+                                        expected_output,
+                                        expected_disk,
+                                        expected_status)
+
+#----------------------------------------------------------------------
+
+
 ########################################################################
 # Run the tests
 
@@ -1979,6 +2135,7 @@
               delete_keep_local,
               windows_paths_in_repos,
               basic_rm_urls_one_repo,
+              automatic_conflict_resolution
              ]
 
 if __name__ == '__main__':
Index: subversion/svn/cl.h
===================================================================
--- subversion/svn/cl.h	(revision 25134)
+++ subversion/svn/cl.h	(working copy)
@@ -159,6 +159,7 @@
   apr_hash_t *revprop_table;     /* table with revision properties to set */
   svn_boolean_t parents;         /* create intermediate directories */
   svn_boolean_t merge_sensitive; /* use/display extra merge information */
+  const char *accept;			 /* automatically resolve conflict with original, wc or repository file */
 
 } svn_cl__opt_state_t;
 
Index: subversion/svn/main.c
===================================================================
--- subversion/svn/main.c	(revision 25134)
+++ subversion/svn/main.c	(working copy)
@@ -207,7 +207,11 @@
   {"merge-sensitive", 'g', 0,
                     N_("use/display additional information from merge "
                        "history")},
-  {0,               0, 0, 0}
+  {"accept", 'a', 1,
+  					N_("specify automatic conflict resolution source\n"
+  					   "                            "
+  					   "('orig', 'mine', or 'repo')")},
+  {0,               0, 0, 0},
 };
 
 
@@ -695,7 +699,7 @@
      "  remove conflict markers; it merely removes the conflict-related\n"
      "  artifact files and allows PATH to be committed again.\n"),
     {svn_cl__targets_opt, 'R', svn_cl__depth_opt, 'q',
-     svn_cl__config_dir_opt} },
+     svn_cl__config_dir_opt, 'a'} },
 
   { "revert", svn_cl__revert, {0}, N_
     ("Restore pristine working copy file (undo most local edits).\n"