XA PREPARE and SHOW STATUS

XA transaction only allows to access data in specific states,
in ACTIVE, but not in IDLE or PREPARE.

But even then one should be able to run SHOW STATUS.

mysql-test/r/xa.result

@@ -317,3 +317,29 @@ XA ROLLBACK 'xid';
 DROP TABLE t1;
 disconnect con1;
 connection default;
+#
+# XA states and SHOW commands
+#
+create table t1 (pk int primary key) engine=innodb;
+xa start 'foo';
+insert t1 set pk=1;
+xa end 'foo';
+xa prepare 'foo';
+show status like 'foo';
+Variable_name	Value
+select table_name,table_comment from information_schema.tables where table_schema='test';
+table_name	t1
+table_comment	
+select table_name,table_rows,table_comment from information_schema.tables where table_schema='test';
+table_name	t1
+table_rows	NULL
+table_comment	XAER_RMFAIL: The command cannot be executed when global transaction is in the  PREPARED state
+Warnings:
+Level	Warning
+Code	1399
+Message	XAER_RMFAIL: The command cannot be executed when global transaction is in the  PREPARED state
+xa commit 'foo';
+drop table t1;
+#
+# End of 10.2 tests
+#

mysql-test/t/xa.test

@@ -470,3 +470,21 @@ DROP TABLE t1;
 connection default;
 
 --source include/wait_until_count_sessions.inc
+
+--echo #
+--echo # XA states and SHOW commands
+--echo #
+create table t1 (pk int primary key) engine=innodb;
+xa start 'foo';
+insert t1 set pk=1;
+xa end 'foo';
+xa prepare 'foo';
+show status like 'foo';
+--query_vertical select table_name,table_comment from information_schema.tables where table_schema='test'
+--query_vertical select table_name,table_rows,table_comment from information_schema.tables where table_schema='test'
+xa commit 'foo';
+drop table t1;
+
+--echo #
+--echo # End of 10.2 tests
+--echo #

sql/sql_base.cc

@@ -3985,13 +3985,19 @@ bool open_tables(THD *thd, const DDL_options_st &options,
   bool has_prelocking_list;
   DBUG_ENTER("open_tables");
 
-  /* Accessing data in XA_IDLE or XA_PREPARED is not allowed. */
-  enum xa_states xa_state= thd->transaction.xid_state.xa_state;
-  if (*start && (xa_state == XA_IDLE || xa_state == XA_PREPARED))
-  {
-    my_error(ER_XAER_RMFAIL, MYF(0), xa_state_names[xa_state]);
-    DBUG_RETURN(true);
-  }
+  /* Data access in XA transaction is only allowed when it is active. */
+  for (TABLE_LIST *table= *start; table; table= table->next_global)
+    if (!table->schema_table)
+    {
+      enum xa_states xa_state= thd->transaction.xid_state.xa_state;
+      if (xa_state == XA_IDLE || xa_state == XA_PREPARED)
+      {
+        my_error(ER_XAER_RMFAIL, MYF(0), xa_state_names[xa_state]);
+        DBUG_RETURN(true);
+      }
+      else
+        break;
+    }
 
   thd->current_tablenr= 0;
 restart: