optionally be specified.
 * If @a hunk_delimiter is NULL, use the default hunk delimiter "@@".
 *
 * As a special case, if the hunk delimiter is "##", then for an incomplete
 * final line use the text "\ No newline at end of property" instead of
 * "\ No newline at end of file".
 *
 * If @a context_size is not negative, then this number of context lines
 * will be used in the generated diff output. Otherwise the legacy compile
 * time default will be used.
 *
 * If not @c NULL, call @a cancel_func with @a cancel_baton once or multiple
 * times while processing larger diffs.
 *
 * Uses @a scratch_pool for temporary allocations.
 *
 * @since New in 1.9
 */
svn_error_t *
svn_diff_mem_string_output_unified3(svn_stream_t *output_stream,
                                    svn_diff_t *diff,
                                    svn_boolean_t with_diff_header,
                                    const char *hunk_delimiter,
                                    const char *original_header,
                                    const char *modified_header,
                                    const char *header_encoding,
                                    const svn_string_t *original,
                                    const svn_string_t *modified,
                                    int context_size,
                                    svn_cancel_func_t cancel_func,
                                    void *cancel_baton,
                                    apr_pool_t *scratch_pool);

/** Similar to svn_diff_mem_string_output_unified3() but without
 * cancel support and with @a context_size set to -1.
 *
 * @since New in 1.7. Hunk delimiter "##" has the special meaning since 1.8.
 *
 * @deprecated Provided for backwards compatibility with the 1.8 API.
 */
SVN_DEPRECATED
svn_error_t *
svn_diff_mem_string_output_unified2(svn_stream_t *output_stream,
                                    svn_diff_t *diff,
                                    svn_boolean_t with_diff_header,
                                    const char *hunk_delimiter,
                                    const char *original_header,
                                    const char *modified_header,
                                    const char *header_encoding,
                                    const svn_string_t *original,
                                    const svn_string_t *modified,
                                    apr_pool_t *pool);

/** Similar to svn_diff_mem_string_output_unified2() but with
 * @a with_diff_header always set to TRUE and @a hunk_delimiter always
 * set to NULL.
 *
 * @since New in 1.5.
 *
 * @deprecated Provided for backwards compatibility with the 1.8 API.
 */
SVN_DEPRECATED
svn_error_t *
svn_diff_mem_string_output_unified(svn_stream_t *output_stream,
                                   svn_diff_t *diff,
                                   const char *original_header,
                                   const char *modified_header,
                                   const char *header_encoding,
                                   const svn_string_t *original,
                                   const svn_string_t *modified,
                                   apr_pool_t *pool);

/** Output the @a diff generated by svn_diff_mem_string_diff3() in diff3
 * format on @a output_stream, using @a original, @a modified and @a latest
 * for content changes.
 *
 * Use the conflict markers @a conflict_original, @a conflict_modified,
 * @a conflict_latest and @a conflict_separator or the default one for
 * each of these if @c NULL is passed.
 *
 * @a conflict_style dictates how conflicts are displayed.
 *
 * If not @c NULL, call @a cancel_func with @a cancel_baton once or multiple
 * times while processing larger diffs.
 *
 * Uses @a scratch_pool for temporary allocations.
 *
 * @since New in 1.9.
 */
svn_error_t *
svn_diff_mem_string_output_merge3(svn_stream_t *output_stream,
                                  svn_diff_t *diff,
                                  const svn_string_t *original,
                                  const svn_string_t *modified,
                                  const svn_string_t *latest,
                                  const char *conflict_original,
                                  const char *conflict_modified,
                                  const char *conflict_latest,
                                  const char *conflict_separator,
                                  svn_diff_conflict_display_style_t style,
                                  svn_cancel_func_t cancel_func,
                                  void *cancel_baton,
                                  apr_pool_t *scratch_pool);

/** Similar to svn_diff_mem_string_output_merge2(), but without cancel support.
 *
 * @since New in 1.6.
 *
 * @deprecated Provided for backwards compatibility with the 1.8 API.
 */
SVN_DEPRECATED
svn_error_t *
svn_diff_mem_string_output_merge2(svn_stream_t *output_stream,
                                  svn_diff_t *diff,
                                  const svn_string_t *original,
                                  const svn_string_t *modified,
                                  const svn_string_t *latest,
                                  const char *conflict_original,
                                  const char *conflict_modified,
                                  const char *conflict_latest,
                                  const char *conflict_separator,
                                  svn_diff_conflict_display_style_t style,
                                  apr_pool_t *pool);

/** Similar to svn_diff_mem_string_output_merge2, but with @a
 * display_original_in_conflict and @a display_resolved_conflicts
 * booleans instead of the @a conflict_style enum.
 *
 * If both booleans are false, acts like
 * svn_diff_conflict_display_modified_latest; if @a
 * display_original_in_conflict is true, acts like
 * svn_diff_conflict_display_modified_original_latest; if @a
 * display_resolved_conflicts is true, acts like
 * svn_diff_conflict_display_resolved_modified_latest.  The booleans
 * may not both be true.
 *
 * @deprecated Provided for backward compatibility with the 1.5 API.
 */
SVN_DEPRECATED
svn_error_t *
svn_diff_mem_string_output_merge(svn_stream_t *output_stream,
                                 svn_diff_t *diff,
                                 const svn_string_t *original,
                                 const svn_string_t *modified,
                                 const svn_string_t *latest,
                                 const char *conflict_original,
                                 const char *conflict_modified,
                                 const char *conflict_latest,
                                 const char *conflict_separator,
                                 svn_boolean_t display_original_in_conflict,
                                 svn_boolean_t display_resolved_conflicts,
                                 apr_pool_t *pool);