xa assert fixes

sql/handler.cc:
  more DBUG
sql/handler.h:
  increase MAX_HA (ha_archive has its handlerton too)
sql/log.cc:
  fix assert

sql/handler.cc

@@ -476,6 +476,9 @@ void ha_close_connection(THD* thd)
 void trans_register_ha(THD *thd, bool all, handlerton *ht_arg)
 {
   THD_TRANS *trans;
+  DBUG_ENTER("trans_register_ha");
+  DBUG_PRINT("enter",("%s", all ? "all" : "stmt"));
+
   if (all)
   {
     trans= &thd->transaction.all;
@@ -496,6 +499,7 @@ void trans_register_ha(THD *thd, bool all, handlerton *ht_arg)
   trans->no_2pc|=(ht_arg->prepare==0);
   if (thd->transaction.xid.is_null())
     thd->transaction.xid.set(thd->query_id);
+  DBUG_VOID_RETURN;
 }
 
 /*
@@ -514,7 +518,7 @@ int ha_prepare(THD *thd)
   if (trans->nht)
   {
     if (trans->no_2pc)
-      return -1;
+      DBUG_RETURN(-1);
     for (; *ht; ht++)
     {
       int err;

sql/handler.h

@@ -97,7 +97,7 @@
   Note: the following includes binlog and closing 0.
   so: innodb+bdb+ndb+binlog+0
 */
-#define MAX_HA 5
+#define MAX_HA 6
 
 /*
   Bits in index_ddl_flags(KEY *wanted_index)

sql/log.cc

@@ -129,11 +129,12 @@ static int binlog_rollback(THD *thd, bool all)
   IO_CACHE *trans_log= (IO_CACHE*)thd->ha_data[binlog_hton.slot];
   DBUG_ENTER("binlog_rollback");
   /*
-    first two conditions here are guaranteed - see trans_register_ha()
-    call below. The third one must be true. If it is not, we're registering
+    First assert is guaranteed - see trans_register_ha() call below.
+    The second must be true. If it is not, we're registering
     unnecessary, doing extra work. The cause should be found and eliminated
   */
-  DBUG_ASSERT(all && mysql_bin_log.is_open() && my_b_tell(trans_log));
+  DBUG_ASSERT(all || !(thd->options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN)));
+  DBUG_ASSERT(mysql_bin_log.is_open() && my_b_tell(trans_log));
   /*
      Update the binary log with a BEGIN/ROLLBACK block if we have
      cached some queries and we updated some non-transactional