branches/5.1: Remove unused field can_be_too_old from read_view_struct.

include/read0read.h

@@ -111,10 +111,6 @@ struct read_view_struct{
 	dulint	undo_no;	/* (0, 0) or if type is VIEW_HIGH_GRANULARITY
 				transaction undo_no when this high-granularity
 				consistent read view was created */
-	ibool	can_be_too_old;	/* TRUE if the system has had to purge old
-				versions which this read view should be able
-				to access: the read view can bump into the
-				DB_MISSING_HISTORY error */
 	dulint	low_limit_no;	/* The view does not need to see the undo
 				logs for transactions whose transaction number
 				is strictly smaller (<) than this value: they

read/read0read.c

@@ -212,7 +212,6 @@ read_view_oldest_copy_or_open_new(
 	view_copy->low_limit_no = old_view->low_limit_no;
 	view_copy->low_limit_id = old_view->low_limit_id;
 
-	view_copy->can_be_too_old = FALSE;
 
 	if (n > 0) {
 		/* The last active transaction has the smallest id: */
@@ -258,8 +257,6 @@ read_view_open_now(
 	view->low_limit_no = trx_sys->max_trx_id;
 	view->low_limit_id = view->low_limit_no;
 
-	view->can_be_too_old = FALSE;
-
 	n = 0;
 	trx = UT_LIST_GET_FIRST(trx_sys->trx_list);
 
@@ -432,8 +429,6 @@ read_cursor_view_create_for_mysql(
 	view->low_limit_no = trx_sys->max_trx_id;
 	view->low_limit_id = view->low_limit_no;
 
-	view->can_be_too_old = FALSE;
-
 	n = 0;
 	trx = UT_LIST_GET_FIRST(trx_sys->trx_list);