This is the final commit for Worklog tasks:

* A more dynamic binlog format which allows small changes (1064)
   * Log session variables in Query_log_event (1063)
It contains a few bugfixes (which I made when running the testsuite).
I carefully updated the results of the testsuite (i.e. I checked for every one,
if the difference between .reject and .result could be explained).
Apparently mysql-test-run --manager is broken in 4.1 and 5.0 currently,
so I could neither run the few tests which require --manager, nor check
that they pass nor modify their .result. But for builds, we don't run
with --manager.
Apart from --manager, the full testsuite passes, with Valgrind too (no errors).
I'm going to push in the next minutes. Remains: update the manual.
Note: by chance I saw that (in 4.1, in 5.0) rpl_get_lock fails when run alone;
this is normal at it makes assumptions on thread ids. I will fix this one day
in 4.1.


mysql-test/r/rpl000015.result:
  result update
mysql-test/r/rpl_change_master.result:
  result update
mysql-test/r/rpl_error_ignored_table.result:
  result update
mysql-test/r/rpl_flush_log_loop.result:
  result update
mysql-test/r/rpl_flush_tables.result:
  result update
mysql-test/r/rpl_loaddata.result:
  result update
mysql-test/r/rpl_loaddata_rule_m.result:
  result update
mysql-test/r/rpl_loaddata_rule_s.result:
  result update
mysql-test/r/rpl_log.result:
  result update
mysql-test/r/rpl_log_pos.result:
  result update
mysql-test/r/rpl_max_relay_size.result:
  result update
mysql-test/r/rpl_relayrotate.result:
  result update
mysql-test/r/rpl_replicate_do.result:
  result update
mysql-test/r/rpl_reset_slave.result:
  result update
mysql-test/r/rpl_rotate_logs.result:
  result update
mysql-test/r/rpl_session_var.result:
  result update
mysql-test/r/rpl_temporary.result:
  result update
mysql-test/r/rpl_trunc_binlog.result:
  result update
mysql-test/r/rpl_until.result:
  result update
mysql-test/r/rpl_user_variables.result:
  result update
mysql-test/t/rpl000010-slave.opt:
  need to wait 2 events, because now we receive a Format_desc on top of the Rotate,
  when replication starts.
mysql-test/t/rpl000015.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_change_master.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_empty_master_crash.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_error_ignored_table.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_flush_log_loop.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_loaddata.test:
  position update
mysql-test/t/rpl_loaddata_rule_m.test:
  position update
mysql-test/t/rpl_loaddata_rule_s.test:
  position update
mysql-test/t/rpl_log.test:
  position update
mysql-test/t/rpl_log_pos.test:
  position update
mysql-test/t/rpl_max_relay_size.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_openssl.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_redirect.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_relayrotate-slave.opt:
  better options for this test
mysql-test/t/rpl_relayrotate.test:
  using max() is better for debugging (it shows at which place the slave
  SQL thread resumed)
mysql-test/t/rpl_replicate_do.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_reset_slave.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_rotate_logs.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_session_var.test:
  100 because password() is longer than 10 chars
mysql-test/t/rpl_trunc_binlog.test:
  relay log information is not repeatable in general (if a reconnection
  happens because --sleep=10 for example), so we hide these columns.
mysql-test/t/rpl_until.test:
  position update
mysql-test/t/rpl_user_variables.test:
  position update
sql/log.cc:
  Ensure that the Format_desc propagated on next relay logs does not trigger
  undue actions (like incrementing some positions or clearing some files).
sql/log_event.cc:
  * When the slave SQL thread finds a Rotate/Format_desc/Stop in the middle of
  a transaction (then these were written by the slave itself to its relay log),
  it should not increment rli->group* variables, but only rli->event* ones.
  * When the slave SQL thread finds a Format_desc not to be ignored (not
  the same server id as the slave's), if it has log_pos==0 it must not trigger
  "unfinished transaction in master's binlog" (log_pos==0 is always a marker
  in the relay log to mean "this event was not at this place in the master's
  binlog": it's for fake Rotate events, and for Format_description events which the master had
  to send us for replication to start).
  * In the Query_log_event on disk, catalog is now terminated by '\0'.
  * thd->catalog must be set to 0 when some exec_event() terminate (otherwise
  double free).
sql/slave.cc:
  * Fixes for a few bugs when ignoring events in the slave SQL thread:
    - do not decrement rli->slave_skip_counter if the event is an event
    related to the binlog or relay log itself (FORMAT_DESCRIPTION,
    ROTATE, STOP) because these events should never be skipped (or the slave
    will be confused). Usually the user wants to skip a query, not a Rotate... 
    - when we (re)connect to the master, we must free description_event_for_queue
    (otherwise memory leak when we reconnect). 
  * Changed a bit the code where we change description_event_for_queue,
  to make it look "safer".
  * Moved 'created=0' to log.cc where it is safer.
  * When the slave SQL thread finds a Rotate/Format_desc/Stop in the middle of
  a transaction (then these were written by the slave itself to its relay log),
  it should not increment rli->group* variables, but only rli->event* ones.
sql/sql_class.h:
  a warning comment
sql/sql_repl.cc:
  A mistake: I had passed a char* instead of char**

sql/sql_repl.cc

@@ -328,30 +328,30 @@ int purge_master_logs_before_date(THD* thd, time_t purge_time)
   return purge_error_message(thd ,res);
 }
 
-int test_for_non_eof_log_read_errors(int error, const char *errmsg)
+int test_for_non_eof_log_read_errors(int error, const char **errmsg)
 {
   if (error == LOG_READ_EOF) 
     return 0;
   my_errno= ER_MASTER_FATAL_ERROR_READING_BINLOG;
   switch (error) {
   case LOG_READ_BOGUS:
-    errmsg = "bogus data in log event";
+    *errmsg = "bogus data in log event";
     break;
   case LOG_READ_TOO_LARGE:
-    errmsg = "log event entry exceeded max_allowed_packet; \
+    *errmsg = "log event entry exceeded max_allowed_packet; \
 Increase max_allowed_packet on master";
     break;
   case LOG_READ_IO:
-    errmsg = "I/O error reading log event";
+    *errmsg = "I/O error reading log event";
     break;
   case LOG_READ_MEM:
-    errmsg = "memory allocation failed reading log event";
+    *errmsg = "memory allocation failed reading log event";
     break;
   case LOG_READ_TRUNC:
-    errmsg = "binlog truncated in the middle of event";
+    *errmsg = "binlog truncated in the middle of event";
     break;
   default:
-    errmsg = "unknown error reading log event on the master";
+    *errmsg = "unknown error reading log event on the master";
     break;
   }
   return error;
@@ -519,7 +519,7 @@ impossible position";
        }
      }
      else
-       if (test_for_non_eof_log_read_errors(error, errmsg))
+       if (test_for_non_eof_log_read_errors(error, &errmsg))
          goto err;
      /* 
         else: it's EOF, nothing to do, go on reading next events, the
@@ -573,7 +573,7 @@ impossible position";
       in the-master-of-this-master's binlog.
     */
 
-    if (test_for_non_eof_log_read_errors(error, errmsg))
+    if (test_for_non_eof_log_read_errors(error, &errmsg))
       goto err;
 
     if (!(flags & BINLOG_DUMP_NON_BLOCK) &&
@@ -1349,7 +1349,10 @@ int show_binlog_events(THD* thd)
     if (ev)
     {
       if (ev->get_type_code() == FORMAT_DESCRIPTION_EVENT)
+      {
+        delete description_event;
         description_event= (Format_description_log_event*) ev;
+      }
       else
         delete ev;
     }