many bug fixes

sql/log.cc:
  Fix for a bug in query logging ...
sql/mysqld.cc:
  Fix for a bug with max_allowed_packt
sql/sql_select.cc:
  Fix for a bug which is caused when a single table is scanned by
  entire index and WHERE clause is so broad that JOIN type is JT_ALL.

sql/log.cc

@@ -963,6 +963,7 @@ bool MYSQL_LOG::write(THD *thd,const char *query, uint query_length,
 	end=strxmov(buff, "# administrator command: ",
 		    command_name[thd->command], NullS);
 	query_length=(ulong) (end-buff);
+	query=buff;
       }
       if (my_b_write(&log_file, (byte*) query,query_length) ||
 	  my_b_write(&log_file, (byte*) ";\n",2) ||

sql/mysqld.cc

@@ -2984,7 +2984,7 @@ CHANGEABLE_VAR changeable_vars[] = {
 #endif
     ,0, 1, 0, 1 },
   { "max_allowed_packet",      (long*) &max_allowed_packet,
-      1024*1024L, 80, 64*1024*1024L, MALLOC_OVERHEAD, 1024 },
+      1024*1024L, 80, 255*255*255L, MALLOC_OVERHEAD, 1024 },
   { "max_binlog_cache_size",   (long*) &max_binlog_cache_size,
       ~0L, IO_SIZE, ~0L, 0, IO_SIZE },
   { "max_binlog_size",         (long*) &max_binlog_size,

sql/sql_select.cc

@@ -2328,7 +2328,8 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
 
 	  if ((tab->keys & ~ tab->const_keys && i > 0) ||
 	      tab->const_keys && i == join->const_tables &&
-	      join->thd->select_limit < join->best_positions[i].records_read)
+	      join->thd->select_limit < join->best_positions[i].records_read &&
+	      join->tables > 1)
 	  {
 	    /* Join with outer join condition */
 	    COND *orig_cond=sel->cond;