import-cmd.c

Rework the path library to accept and return "" as the only canonical
empty path. Make sure the client canonicalizes all paths passed to
the libraries. The path library now assumes that its inputs are
canonical. Remove the use of explicit "." except for a few special
cases.

* subversion/include/svn_path.h (svn_path_join, svn_path_split,
svn_path_is_empty, svn_path_is_single_path_component,
svn_path_split_if_file, svn_path_url_add_component): Tweak documentation.

* subversion/libsvn_subr/path.c
(SVN_EMPTY_PATH, SVN_PATH_IS_EMPTY, SVN_PATH_IS_PLATFORM_EMPTY): New macros.

(SVN_PATH_SEPARATOR): Delete macro as we cannot change the separator. Change
all uses in the file to an explicit '/'.

(discount_trailing_dot_slash, is_canonical_nts): New functions.

(svn_path_canonicalize, svn_path_canonicalize_nts): Strip trailing
dots as well as slashes, convert "." to "".

(svn_path_join_many): Rework without considering ".".

(add_component_internal): No need to canonicalize.

(svn_path_remove_component, svn_path_remove_component_nts): No need
to canonicalize input. After removing component, strip trailing dots
and slashes, and convert "." to "".

(svn_path_basename): Convert "." to "".

(svn_path_split): No need to canonicalize input.

(svn_path_get_longest_ancestor): No need to canonicalize inputs.

(svn_path_decompose): Convert "." to "".

(svn_path_split_if_file): Return "" as empty path if input is a
directory.

(svn_path_url_add_component): Canonicalize input URL.

(svn_path_internal_style, svn_path_local_style, svn_path_join,
svn_path_is_empty, svn_path_is_empty_nts, svn_path_compare_paths,
svn_path_compare_paths_nts, svn_path_is_child,
svn_path_is_single_path_component): Change to use new macros, or to
use explicit '/', or to assert canonical input.

* subversion/clients/cmdline/util.c
(svn_cl__args_to_target_array): Add canonicalization of paths. Move
svn_path_basename call after UTF-8 and canonicalization.
(svn_cl__edit_externally): Convert "" to "." to satisfy APR.

* subversion/tests/libsvn_subr/path-test.c
(SVN_EMPTY_PATH): New macro.

(test_path_split): Remove non-canonical inputs. Add new tests. Test
svn_path_split_nts as well.

(test_join, test_basename): Remove non-canonical inputs. Add new tests.

(test_canonicalize): New test.

* subversion/libsvn_subr/io.c (svn_io_remove_dir, svn_io_stat, svn_io_dir_open,
apr_dir_is_empty): Convert "" to "." to satisfy APR.

* subversion/libsvn_client/update.c (svn_client_update): Accept "" path.

* subversion/mod_dav_svn/update.c (get_from_path_map): Break on "/". How did
this ever work before?

* subversion/clients/cmdline/revert-cmd.c (svn_cl__revert): Delete
svn_path_canonicalize_nts call.

* subversion/clients/cmdline/update-cmd.c (svn_cl__update): Delete
svn_path_canonicalize_nts call.


Replace explicit "." with "" and remove the construct

if (svn_path_is_empty_nts(path))
path = "."

from the following files

* subversion/libsvn_wc/entries.c
* subversion/libsvn_wc/adm_ops.c
* subversion/libsvn_wc/adm_files.c
* subversion/libsvn_wc/update_editor.c
* subversion/libsvn_client/switch.c
* subversion/libsvn_client/ra.c
* subversion/libsvn_client/delete.c
* subversion/libsvn_client/diff.c
* subversion/libsvn_client/copy.c
* subversion/libsvn_client/repos_diff.c
* subversion/libsvn_client/commit_util.c
* subversion/libsvn_client/commit.c
* subversion/libsvn_client/add.c
* subversion/libsvn_client/commit.c
* subversion/clients/cmdline/merge-cmd.c
* subversion/clients/cmdline/checkout-cmd.c
* subversion/clients/cmdline/switch-cmd.c
* subversion/clients/cmdline/import-cmd.c
* subversion/libsvn_ra_dav/fetch.c
* subversion/libsvn_ra_dav/commit.c