MDEV-22562 Assertion `next_insert_id == 0' upon UPDATE on system-versioned table

Don't update autoinc counter on history row insert. Uniqueness is kept
due to merge with row_end.

mysql-test/suite/versioning/r/auto_increment.result → mysql-test/suite/versioning/r/autoinc.result

@@ -63,3 +63,13 @@ A	x	y	x	y
 1	7	17	7	17
 drop table t1;
 drop table t2;
+#
+# MDEV-22562 Assertion `next_insert_id == 0' upon UPDATE on system-versioned table
+#
+create table t1 (pk integer auto_increment primary key) engine=myisam with system versioning;
+insert delayed into t1 (pk) values (1);
+lock tables t1 write;
+update t1 set pk= 0;
+update t1 set pk= 0;
+unlock tables;
+drop table t1;

mysql-test/suite/versioning/t/auto_increment.test → mysql-test/suite/versioning/t/autoinc.test

@@ -47,4 +47,17 @@ select t1.x = t2.x and t1.y = t2.y as A, t1.x, t1.y, t2.x, t2.y from t1 inner jo
 drop table t1;
 drop table t2;
 
+--echo #
+--echo # MDEV-22562 Assertion `next_insert_id == 0' upon UPDATE on system-versioned table
+--echo #
+create table t1 (pk integer auto_increment primary key) engine=myisam with system versioning;
+insert delayed into t1 (pk) values (1);
+lock tables t1 write;
+update t1 set pk= 0;
+update t1 set pk= 0;
+unlock tables;
+
+# cleanup
+drop table t1;
+
 -- source suite/versioning/common_finish.inc

sql/handler.cc

@@ -3326,25 +3326,27 @@ int handler::update_auto_increment()
     DBUG_RETURN(0);
   }
 
-  // ALTER TABLE ... ADD COLUMN ... AUTO_INCREMENT
-  if (thd->lex->sql_command == SQLCOM_ALTER_TABLE)
+  if (table->versioned())
   {
-    if (table->versioned())
+    Field *end= table->vers_end_field();
+    DBUG_ASSERT(end);
+    bitmap_set_bit(table->read_set, end->field_index);
+    if (!end->is_max())
     {
-      Field *end= table->vers_end_field();
-      DBUG_ASSERT(end);
-      bitmap_set_bit(table->read_set, end->field_index);
-      if (!end->is_max())
+      if (thd->lex->sql_command == SQLCOM_ALTER_TABLE)
       {
         if (!table->next_number_field->real_maybe_null())
           DBUG_RETURN(HA_ERR_UNSUPPORTED);
         table->next_number_field->set_null();
-        DBUG_RETURN(0);
       }
+      DBUG_RETURN(0);
     }
-    table->next_number_field->set_notnull();
   }
 
+  // ALTER TABLE ... ADD COLUMN ... AUTO_INCREMENT
+  if (thd->lex->sql_command == SQLCOM_ALTER_TABLE)
+    table->next_number_field->set_notnull();
+
   if ((nr= next_insert_id) >= auto_inc_interval_for_cur_row.maximum())
   {
     /* next_insert_id is beyond what is reserved, so we reserve more. */