MDEV-12008 fixup: Do not add a new error code

New error codes can only be added in the latest major version.
Adding ER_KILL_DENIED_HIGH_PRIORITY would shift by one all
error codes that were added in MariaDB Server 10.6 or later.

This amends commit 1001dae186

Suggested by: Sergei Golubchik

mysql-test/suite/galera/r/galera_kill_applier.result

@@ -6,13 +6,13 @@ SELECT @@wsrep_slave_threads;
 1
 SET GLOBAL wsrep_slave_threads=2;
 KILL ID;
-ERROR HY000: This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster
+ERROR HY000: This is a high priority thread/query and cannot be killed without compromising the consistency of the cluster
 KILL QUERY ID;
-ERROR HY000: This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster
+ERROR HY000: This is a high priority thread/query and cannot be killed without compromising the consistency of the cluster
 KILL ID;
-ERROR HY000: This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster
+ERROR HY000: This is a high priority thread/query and cannot be killed without compromising the consistency of the cluster
 KILL QUERY ID;
-ERROR HY000: This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster
+ERROR HY000: This is a high priority thread/query and cannot be killed without compromising the consistency of the cluster
 SET GLOBAL wsrep_slave_threads=DEFAULT;
 connection node_1;
 create table t1(a int not null primary key) engine=innodb;

mysql-test/suite/galera/r/galera_kill_bf.result

@@ -10,9 +10,9 @@ connection node_1;
 SET SESSION wsrep_sync_wait = 0;
 SET DEBUG_SYNC = 'now WAIT_FOR bf_started';
 KILL ID;
-ERROR HY000: This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster
+ERROR HY000: This is a high priority thread/query and cannot be killed without compromising the consistency of the cluster
 KILL QUERY ID;
-ERROR HY000: This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster
+ERROR HY000: This is a high priority thread/query and cannot be killed without compromising the consistency of the cluster
 connection node_1;
 SET DEBUG_SYNC = 'now SIGNAL bf_continue';
 connection con1;

mysql-test/suite/galera/t/galera_kill_applier.test

@@ -17,21 +17,21 @@ SET GLOBAL wsrep_slave_threads=2;
 --let $applier_thread = `SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle' LIMIT 1`
 
 --replace_result $applier_thread ID
---error ER_KILL_DENIED_HIGH_PRIORITY
+--error ER_KILL_DENIED_ERROR
 --eval KILL $applier_thread
 
 --replace_result $applier_thread ID
---error ER_KILL_DENIED_HIGH_PRIORITY
+--error ER_KILL_DENIED_ERROR
 --eval KILL QUERY $applier_thread
 
 --let $aborter_thread = `SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep aborter idle' LIMIT 1`
 
 --replace_result $aborter_thread ID
---error ER_KILL_DENIED_HIGH_PRIORITY
+--error ER_KILL_DENIED_ERROR
 --eval KILL $aborter_thread
 
 --replace_result $aborter_thread ID
---error ER_KILL_DENIED_HIGH_PRIORITY
+--error ER_KILL_DENIED_ERROR
 --eval KILL QUERY $aborter_thread
 
 SET GLOBAL wsrep_slave_threads=DEFAULT;

mysql-test/suite/galera/t/galera_kill_bf.test

@@ -21,11 +21,11 @@ SET DEBUG_SYNC = 'now WAIT_FOR bf_started';
 --let $applier_thread = `SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST WHERE STATE LIKE 'debug sync point:%' LIMIT 1`
 
 --replace_result $applier_thread ID
---error ER_KILL_DENIED_HIGH_PRIORITY
+--error ER_KILL_DENIED_ERROR
 --eval KILL $applier_thread
 
 --replace_result $applier_thread ID
---error ER_KILL_DENIED_HIGH_PRIORITY
+--error ER_KILL_DENIED_ERROR
 --eval KILL QUERY $applier_thread
 
 --connection node_1

sql/share/errmsg-utf8.txt

@@ -9111,5 +9111,3 @@ ER_NOT_ALLOWED_IN_THIS_CONTEXT
         eng "'%-.128s' is not allowed in this context"
 ER_DATA_WAS_COMMITED_UNDER_ROLLBACK
         eng "Engine %s does not support rollback. Changes were committed during rollback call"
-ER_KILL_DENIED_HIGH_PRIORITY
-        eng "This is a high-priority thread/query and cannot be killed without compromising the consistency of the cluster"

sql/sql_parse.cc

@@ -9379,8 +9379,12 @@ THD *find_thread_by_id(longlong id, bool query_id)
   @param type                   Type of id: thread id or query id
 */
 
-uint
-kill_one_thread(THD *thd, my_thread_id id, killed_state kill_signal, killed_type type)
+static uint
+kill_one_thread(THD *thd, my_thread_id id, killed_state kill_signal, killed_type type
+#ifdef WITH_WSREP
+                , bool &wsrep_high_priority
+#endif
+)
 {
   THD *tmp;
   uint error= (type == KILL_TYPE_QUERY ? ER_NO_SUCH_QUERY : ER_NO_SUCH_THREAD);
@@ -9421,9 +9425,10 @@ kill_one_thread(THD *thd, my_thread_id id, killed_state kill_signal, killed_type
 #ifdef WITH_WSREP
       if (wsrep_thd_is_BF(tmp, false) || tmp->wsrep_applier)
       {
-        error= ER_KILL_DENIED_HIGH_PRIORITY;
+        error= ER_KILL_DENIED_ERROR;
+        wsrep_high_priority= true;
         push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
-                            ER_KILL_DENIED_HIGH_PRIORITY,
+                            ER_KILL_DENIED_ERROR,
                             "Thread %lld is %s and cannot be killed",
                             tmp->thread_id,
                            (tmp->wsrep_applier ? "wsrep applier" : "high priority"));
@@ -9562,14 +9567,28 @@ static uint kill_threads_for_user(THD *thd, LEX_USER *user,
 static
 void sql_kill(THD *thd, my_thread_id id, killed_state state, killed_type type)
 {
-  uint error;
-  if (likely(!(error= kill_one_thread(thd, id, state, type))))
+#ifdef WITH_WSREP
+  bool wsrep_high_priority= false;
+#endif
+  uint error= kill_one_thread(thd, id, state, type
+#ifdef WITH_WSREP
+                              , wsrep_high_priority
+#endif
+                              );
+
+  if (likely(!error))
   {
     if (!thd->killed)
       my_ok(thd);
     else
       thd->send_kill_message();
   }
+#ifdef WITH_WSREP
+  else if (wsrep_high_priority)
+    my_printf_error(error, "This is a high priority thread/query and"
+                    " cannot be killed without compromising"
+                    " the consistency of the cluster", MYF(0));
+#endif
   else
   {
     my_error(error, MYF(0), id);