MDEV-22714 Assertion failed upon multi-update on table WITHOUT OVERLAPS

The problem here was that ha_check_overlaps internally uses ha_index_read,
which in case of fail overwrites table->status. Even though the handlers
are different, they share a common table, so the value is anyway spoiled.
This is bad, and table->status is badly designed and overweighted by
functionality, but nothing can be done with it, since the code related to
this logic is ancient and it's impossible to extract it with normal effort.

So let's just save and restore the value in ha_update_row before and after
the checks.

Other operations like INSERT and simple UPDATE are not in risk, since they
don't use this table->status approach.
DELETE does not do any unique checks, so it's also safe.

3 files changed, 32 insertions, 6 deletions

diff --git a/mysql-test/suite/period/r/overlaps.result b/mysql-test/suite/period/r/overlaps.result
index fcd54a0a942..f5839a84e4b 100644
--- a/mysql-test/suite/period/r/overlaps.result
+++ b/mysql-test/suite/period/r/overlaps.result
@@ -320,4 +320,13 @@ t1	CREATE TABLE `t1` (
  PARTITION `pn` CURRENT ENGINE = InnoDB)
 insert into t1 values (1,'2013-01-12','2015-11-04'),
 (2,'2016-03-15','2024-11-09');
+# MDEV-22714 Assertion `index->table->is_instant()' failed upon
+# multi-update on table with WITHOUT OVERLAPS
+create or replace table t (a int);
+insert into t values (0),(null),(0);
+create or replace table t1 (f int, s date, e date, period for p(s,e),
+unique(f, p without overlaps));
+insert into t1 values (0,'2026-02-12','2036-09-16'),
+(null,'2025-03-09','2032-12-05');
+update ignore t join t1 set f = a;
 drop table t, t1;
diff --git a/mysql-test/suite/period/t/overlaps.test b/mysql-test/suite/period/t/overlaps.test
index 30032f9898c..ef2161d27a2 100644
--- a/mysql-test/suite/period/t/overlaps.test
+++ b/mysql-test/suite/period/t/overlaps.test
@@ -299,5 +299,19 @@ insert into t1 values (1,'2013-01-12','2015-11-04'),
                       (2,'2016-03-15','2024-11-09');
 
 
+--echo # MDEV-22714 Assertion `index->table->is_instant()' failed upon
+--echo # multi-update on table with WITHOUT OVERLAPS
+
+create or replace table t (a int);
+insert into t values (0),(null),(0);
+
+create or replace table t1 (f int, s date, e date, period for p(s,e),
+                            unique(f, p without overlaps));
+
+insert into t1 values (0,'2026-02-12','2036-09-16'),
+                      (null,'2025-03-09','2032-12-05');
+
+update ignore t join t1 set f = a;
+
 
 drop table t, t1;
diff --git a/sql/handler.cc b/sql/handler.cc
index c33dcb192d8..aa04b0bce1c 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -7182,17 +7182,20 @@ int handler::ha_update_row(const uchar *old_data, const uchar *new_data)
   DBUG_ASSERT(new_data == table->record[0]);
   DBUG_ASSERT(old_data == table->record[1]);
 
-  if ((error= ha_check_overlaps(old_data, new_data)))
-    return error;
+  uint saved_status= table->status;
+  error= ha_check_overlaps(old_data, new_data);
 
   MYSQL_UPDATE_ROW_START(table_share->db.str, table_share->table_name.str);
   mark_trx_read_write();
   increment_statistics(&SSV::ha_update_count);
-  if (table->s->long_unique_table && this == table->file &&
-      (error= check_duplicate_long_entries_update(new_data)))
-  {
+
+  if (!error && table->s->long_unique_table && this == table->file)
+    error= check_duplicate_long_entries_update(new_data);
+  table->status= saved_status;
+
+  if (error)
     return error;
-  }
+
 
   TABLE_IO_WAIT(tracker, PSI_TABLE_UPDATE_ROW, active_index, 0,
                       { error= update_row(old_data, new_data);})