MDEV-21098: Assertion failure in rec_get_offsets_func()

The function rec_get_offsets_func() used to hit ut_error
due to an invalid rec_get_status() value of a
ROW_FORMAT!=REDUNDANT record. This fix is twofold:
We will not only avoid a crash on corruption in this case,
but we will also make more effort to validate each record
every time we are iterating over index page records.

rec_get_offsets_func(): Do not crash on a corrupted record.

page_rec_get_nth(): Return nullptr on error.

page_dir_slot_get_rec_validate(): Like page_dir_slot_get_rec(),
but validate the pointer and return nullptr on error.

page_cur_search_with_match(), page_cur_search_with_match_bytes(),
page_dir_split_slot(), page_cur_move_to_next():
Indicate failure in a return value.

page_cur_search(): Replaced with page_cur_search_with_match().

rec_get_next_ptr_const(), rec_get_next_ptr(): Replaced with
page_rec_get_next_low().

TODO: rtr_page_split_initialize_nodes(), rtr_update_mbr_field(),
and possibly other SPATIAL INDEX functions fail to properly handle
errors.

Reviewed by: Thirunarayanan Balathandayuthapani
Tested by: Matthias Leich
Performance tested by: Axel Schwenke

1 files changed, 6 insertions, 6 deletions

diff --git a/storage/innobase/rem/rem0rec.cc b/storage/innobase/rem/rem0rec.cc
index bd572372aca..9948f2e4d68 100644
--- a/storage/innobase/rem/rem0rec.cc
+++ b/storage/innobase/rem/rem0rec.cc
@@ -864,19 +864,19 @@ rec_get_offsets_func(
 			ut_ad(!n_core);
 			n = dict_index_get_n_unique_in_tree_nonleaf(index) + 1;
 			break;
+		default:
+			ut_ad("corrupted record header" == 0);
+			/* fall through */
 		case REC_STATUS_INFIMUM:
 		case REC_STATUS_SUPREMUM:
 			/* infimum or supremum record */
 			ut_ad(rec_get_heap_no_new(rec)
 			      == ulint(rec_get_status(rec)
-                                       == REC_STATUS_INFIMUM
-                                       ? PAGE_HEAP_NO_INFIMUM
-                                       : PAGE_HEAP_NO_SUPREMUM));
+				       == REC_STATUS_INFIMUM
+				       ? PAGE_HEAP_NO_INFIMUM
+				       : PAGE_HEAP_NO_SUPREMUM));
 			n = 1;
 			break;
-		default:
-			ut_error;
-			return(NULL);
 		}
 	} else {
 		n = rec_get_n_fields_old(rec);