MDEV-26866 FOREIGN KEY…SET NULL corrupts an index on a virtual column

The initial test case for MySQL Bug #33053297 is based on
mysql/mysql-server@27130e25078864b010d81266f9613d389d4a229b.

innobase_get_field_from_update_vector is not a suitable function to fetch
updated row info, as well as parent table's update vector is not always
suitable. For instance, in case of DELETE it contains undefined data.

castade->update vector seems to be good enough to fetch all base columns
update data, and besides faster, and less error-prone.

5 files changed, 13 insertions, 15 deletions

diff --git a/storage/innobase/row/row0ins.cc b/storage/innobase/row/row0ins.cc
index 929d3683ce6..cbe6577c02a 100644
--- a/storage/innobase/row/row0ins.cc
+++ b/storage/innobase/row/row0ins.cc
@@ -898,7 +898,6 @@ row_ins_invalidate_query_cache(
 	innobase_invalidate_query_cache(thr_get_trx(thr), name, len);
 }
 
-
 /** Fill virtual column information in cascade node for the child table.
 @param[out]	cascade		child update node
 @param[in]	rec		clustered rec of child table
@@ -945,6 +944,11 @@ row_ins_foreign_fill_virtual(
 	if (!record) {
 		return DB_OUT_OF_MEMORY;
 	}
+	ut_ad(!node->is_delete
+	      || (foreign->type & DICT_FOREIGN_ON_DELETE_SET_NULL));
+	ut_ad(foreign->type & (DICT_FOREIGN_ON_DELETE_SET_NULL
+			       | DICT_FOREIGN_ON_UPDATE_SET_NULL
+			       | DICT_FOREIGN_ON_UPDATE_CASCADE));
 
 	for (ulint i = 0; i < n_v_fld; i++) {
 
@@ -960,7 +964,7 @@ row_ins_foreign_fill_virtual(
 		dfield_t*	vfield = innobase_get_computed_value(
 				update->old_vrow, col, index,
 				&vc.heap, update->heap, NULL, thd, mysql_table,
-                                record, NULL, NULL, NULL);
+				record, NULL, NULL);
 
 		if (vfield == NULL) {
 			return DB_COMPUTE_VALUE_FAILED;
@@ -976,16 +980,11 @@ row_ins_foreign_fill_virtual(
 
 		upd_field_set_v_field_no(upd_field, i, index);
 
-		bool set_null =
-			node->is_delete
-			? (foreign->type & DICT_FOREIGN_ON_DELETE_SET_NULL)
-			: (foreign->type & DICT_FOREIGN_ON_UPDATE_SET_NULL);
-
 		dfield_t* new_vfield = innobase_get_computed_value(
 				update->old_vrow, col, index,
 				&vc.heap, update->heap, NULL, thd,
 				mysql_table, record, NULL,
-				set_null ? update : node->update, foreign);
+				update);
 
 		if (new_vfield == NULL) {
 			return DB_COMPUTE_VALUE_FAILED;
diff --git a/storage/innobase/row/row0merge.cc b/storage/innobase/row/row0merge.cc
index 9e6179585b1..faa148cca24 100644
--- a/storage/innobase/row/row0merge.cc
+++ b/storage/innobase/row/row0merge.cc
@@ -600,8 +600,8 @@ error:
 				row_field = innobase_get_computed_value(
 					row, v_col, clust_index,
 					v_heap, NULL, ifield, trx->mysql_thd,
-					my_table, vcol_storage.innobase_record, 
-					old_table, NULL, NULL);
+					my_table, vcol_storage.innobase_record,
+					old_table, NULL);
 
 				if (row_field == NULL) {
 					*err = DB_COMPUTE_VALUE_FAILED;
diff --git a/storage/innobase/row/row0sel.cc b/storage/innobase/row/row0sel.cc
index 83bf18ab9b8..87c67edff4b 100644
--- a/storage/innobase/row/row0sel.cc
+++ b/storage/innobase/row/row0sel.cc
@@ -328,7 +328,7 @@ row_sel_sec_rec_is_for_clust_rec(
 					&heap, NULL, NULL,
 					thr_get_trx(thr)->mysql_thd,
 					thr->prebuilt->m_mysql_table,
-					record, NULL, NULL, NULL);
+					record, NULL, NULL);
 
 			if (vfield == NULL) {
 				innobase_report_computed_value_failed(row);
diff --git a/storage/innobase/row/row0upd.cc b/storage/innobase/row/row0upd.cc
index a58c3993e90..0a79225da8c 100644
--- a/storage/innobase/row/row0upd.cc
+++ b/storage/innobase/row/row0upd.cc
@@ -1149,7 +1149,7 @@ row_upd_build_difference_binary(
 			dfield_t*	vfield = innobase_get_computed_value(
 				update->old_vrow, col, index,
 				&vc.heap, heap, NULL, thd, mysql_table, record,
-				NULL, NULL, NULL);
+				NULL, NULL);
 			if (vfield == NULL) {
 				*error = DB_COMPUTE_VALUE_FAILED;
 				return(NULL);
@@ -2175,8 +2175,7 @@ row_upd_store_v_row(
 							node->row, col, index,
 							&vc.heap, node->heap,
 							NULL, thd, mysql_table,
-							record, NULL, NULL,
-							NULL);
+							record, NULL, NULL);
 					if (vfield == NULL) {
 						return false;
 					}
diff --git a/storage/innobase/row/row0vers.cc b/storage/innobase/row/row0vers.cc
index b9bc8418366..bf229966525 100644
--- a/storage/innobase/row/row0vers.cc
+++ b/storage/innobase/row/row0vers.cc
@@ -491,7 +491,7 @@ row_vers_build_clust_v_col(
 			dfield_t *vfield = innobase_get_computed_value(
 				row, col, clust_index, &vc.heap,
 				heap, NULL, thd, maria_table, record, NULL,
-				NULL, NULL);
+				NULL);
 			if (vfield == NULL) {
 				innobase_report_computed_value_failed(row);
 				ut_ad(0);