Follow-up to MDEV-14799: Remove bogus debug assertions

trx_undo_rec_get_partial_row(): When the PRIMARY KEY includes a
column prefix of an externally stored column, the already parsed
part of the undo log record may contain a reference to
an off-page column. This is the case in the bug58912 test in
innodb.innodb.

storage/innobase/trx/trx0rec.c

@@ -1100,9 +1100,6 @@ trx_undo_rec_get_partial_row(
 
 	for (; uf != ue; uf++) {
 		ulint c = dict_index_get_nth_col(index, uf->field_no)->ind;
-		ut_ad(uf->orig_len == UNIV_SQL_NULL
-		      || uf->orig_len < UNIV_EXTERN_STORAGE_FIELD);
-		ut_ad(!dfield_is_ext(&uf->new_val));
 		*dtuple_get_nth_field(*row, c) = uf->new_val;
 	}
 

storage/xtradb/trx/trx0rec.c

@@ -1113,9 +1113,6 @@ trx_undo_rec_get_partial_row(
 
 	for (; uf != ue; uf++) {
 		ulint c = dict_index_get_nth_col(index, uf->field_no)->ind;
-		ut_ad(uf->orig_len == UNIV_SQL_NULL
-		      || uf->orig_len < UNIV_EXTERN_STORAGE_FIELD);
-		ut_ad(!dfield_is_ext(&uf->new_val));
 		*dtuple_get_nth_field(*row, c) = uf->new_val;
 	}