client side workaround for svnserve iprops bug

philip_at_apache.org writes:

> Author: philip
> Date: Tue Mar 18 12:57:22 2014
> New Revision: 1578853
>
> URL: http://svn.apache.org/r1578853
> Log:
> Make svnserve recognise when the client does not want inherited
> properties. This fixes a performance problem with 1.8 servers
> sending too much data.

An implementation bug causes svnserve to mishandle the nominally
optional want-iprops flag for get-dir and get-file with the result that
the server keeps sending properties even when the client doesn't want
them, this can be a serious performance regression. (The want-iprops
flags was documented/released with 1.8 but isn't used by the released
client which uses get-iprops instead.) The problem is fixed on trunk
and nominated for 1.8 with 1578853.

We could add a client-side workaround for buggy servers, see the patch
below. We could do this for trunk, 1.8, even 1.7. Is it a good thing
to do?

Index: subversion/libsvn_ra_svn/client.c
===================================================================
--- subversion/libsvn_ra_svn/client.c (revision 1578900)
+++ subversion/libsvn_ra_svn/client.c (working copy)
@@ -1371,7 +1371,10 @@ static svn_error_t *ra_svn_get_dir(svn_ra_session_
   if (dirent_fields & SVN_DIRENT_LAST_AUTHOR)
     SVN_ERR(svn_ra_svn__write_word(conn, pool, SVN_RA_SVN_DIRENT_LAST_AUTHOR));
 
- SVN_ERR(svn_ra_svn__write_tuple(conn, pool, "!))"));
+ /* Always send the, nominally optional, want-iprops as "false" to
+ workaround a bug in svnserve 1.8.0-1.8.9 that causes the server
+ to see "true" if it omitted. */
+ SVN_ERR(svn_ra_svn__write_tuple(conn, pool, "!)b)", FALSE));
 
   SVN_ERR(handle_auth_request(sess_baton, pool));
   SVN_ERR(svn_ra_svn__read_cmd_response(conn, pool, "rll", &rev, &proplist,
Index: subversion/libsvn_ra_svn/marshal.c
===================================================================
--- subversion/libsvn_ra_svn/marshal.c (revision 1578900)
+++ subversion/libsvn_ra_svn/marshal.c (working copy)
@@ -2092,7 +2092,10 @@ svn_ra_svn__write_cmd_get_file(svn_ra_svn_conn_t *
   SVN_ERR(write_tuple_end_list(conn, pool));
   SVN_ERR(write_tuple_boolean(conn, pool, props));
   SVN_ERR(write_tuple_boolean(conn, pool, stream));
- SVN_ERR(writebuf_write_short_string(conn, pool, ") ) ", 4));
+ /* Always send the, nominally optional, want-iprops as "false" to
+ workaround a bug in svnserve 1.8.0-1.8.9 that causes the server
+ to see "true" if it omitted. */
+ SVN_ERR(writebuf_write_short_string(conn, pool, " false ) ) ", 11));
 
   return SVN_NO_ERROR;
 }

-- 
Philip Martin | Subversion Committer
WANdisco // *Non-Stop Data*