MDEV-15168 Unexpected ER_VERS_ENGINE_UNSUPPORTED upon dropping versioning on a partitioned table

Vers_parse_info::fix_alter_info(): disallow DROP SYSTEM VERSIONING
for system_time partitioned tables.

mysql-test/suite/versioning/r/partition.result

@@ -542,6 +542,13 @@ partition by system_time limit 100 (partition p1 history, partition pn current);
 insert into t1 values (1,10), (2,20);
 create or replace view v1 as select * from t1;
 update v1 set f= 30;
+#
+# MDEV-15168 Unexpected ER_VERS_ENGINE_UNSUPPORTED upon dropping versioning on a partitioned table
+#
+create or replace table t (a int) with system versioning
+partition by system_time (partition p1 history, partition pn current);
+alter table t drop system versioning;
+ERROR HY000: Can not DROP SYSTEM VERSIONING for table `t` partitioned BY SYSTEM_TIME
 # Test cleanup
 drop database test;
 create database test;

mysql-test/suite/versioning/t/partition.test

@@ -454,6 +454,14 @@ insert into t1 values (1,10), (2,20);
 create or replace view v1 as select * from t1;
 update v1 set f= 30;
 
+--echo #
+--echo # MDEV-15168 Unexpected ER_VERS_ENGINE_UNSUPPORTED upon dropping versioning on a partitioned table
+--echo #
+create or replace table t (a int) with system versioning
+  partition by system_time (partition p1 history, partition pn current);
+--error ER_DROP_VERSIONING_SYSTEM_TIME_PARTITION
+alter table t drop system versioning;
+
 --echo # Test cleanup
 drop database test;
 create database test;

sql/handler.cc

@@ -7167,6 +7167,14 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
       my_error(ER_VERS_NOT_VERSIONED, MYF(0), table_name);
       return true;
     }
+#ifdef WITH_PARTITION_STORAGE_ENGINE
+    if (table->part_info &&
+        table->part_info->part_type == VERSIONING_PARTITION)
+    {
+      my_error(ER_DROP_VERSIONING_SYSTEM_TIME_PARTITION, MYF(0), table_name);
+      return true;
+    }
+#endif
 
     return false;
   }

sql/share/errmsg-utf8.txt

@@ -7882,8 +7882,8 @@ ER_VERS_NO_TRX_ID
 ER_VERS_ALTER_SYSTEM_FIELD
         eng "Can not change system versioning field %`s"
 
-ER_UNUSED_24
-        eng "You should never see it"
+ER_DROP_VERSIONING_SYSTEM_TIME_PARTITION
+        eng "Can not DROP SYSTEM VERSIONING for table %`s partitioned BY SYSTEM_TIME"
 
 ER_NOT_LOG_TABLE
         eng "Table %`s.%`s is not a log table"