From 2bb0e7135802d64ad7c1c633059e1f29b3062858 Mon Sep 17 00:00:00 2001
From: Daniel Black <grooverdan@users.sourceforge.net>
Date: Thu, 12 Mar 2015 07:08:31 +1100
Subject: [PATCH] Alter online table x (no options) possible

This no-op of an operations should be able to occur without locks and
occur online.
---
 mysql-test/r/alter_table_online.result | 1 +
 mysql-test/t/alter_table_online.test   | 6 +++++-
 sql/sql_table.cc                       | 4 +++-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/mysql-test/r/alter_table_online.result b/mysql-test/r/alter_table_online.result
index 02c7e5ac691..9d5b2a98af6 100644
--- a/mysql-test/r/alter_table_online.result
+++ b/mysql-test/r/alter_table_online.result
@@ -11,6 +11,7 @@ alter online table t1 comment "new comment";
 ERROR 0A000: LOCK=NONE/SHARED is not supported for this operation. Try LOCK=EXCLUSIVE.
 alter online table t1 rename to t2;
 ERROR 0A000: LOCK=NONE/SHARED is not supported for this operation. Try LOCK=EXCLUSIVE.
+alter online table t1 algorithm=INPLACE, lock=NONE;
 drop table t1;
 create temporary table t1 (a int not null primary key, b int, c varchar(80), e enum('a','b'));
 insert into t1 (a) values (1),(2),(3);
diff --git a/mysql-test/t/alter_table_online.test b/mysql-test/t/alter_table_online.test
index be8037abe11..96700eff02c 100644
--- a/mysql-test/t/alter_table_online.test
+++ b/mysql-test/t/alter_table_online.test
@@ -7,7 +7,7 @@
 drop table if exists t1,t2,t3;
 --enable_warnings
 #
-# Test of things that can be done online
+# Test of things that can not be done online
 #
 
 create table t1 (a int not null primary key, b int, c varchar(80), e enum('a','b'));
@@ -24,6 +24,10 @@ alter online table t1 comment "new comment";
 --error ER_ALTER_OPERATION_NOT_SUPPORTED
 alter online table t1 rename to t2;
 
+# No OPs
+
+alter online table t1 algorithm=INPLACE, lock=NONE;
+
 drop table t1;
 
 #
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 46591e8b5c1..1dd2b16608d 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -8431,6 +8431,7 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
   THD_STAGE_INFO(thd, stage_setup);
   if (!(alter_info->flags & ~(Alter_info::ALTER_RENAME |
                               Alter_info::ALTER_KEYS_ONOFF)) &&
+      alter_info->flags != 0 &&
       alter_info->requested_algorithm !=
       Alter_info::ALTER_TABLE_ALGORITHM_COPY &&
       !table->s->tmp_table) // no need to touch frm
@@ -8449,7 +8450,8 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
     DBUG_RETURN(res);
   }
 
-  handle_if_exists_options(thd, table, alter_info);
+  if (alter_info->flags != 0)
+    handle_if_exists_options(thd, table, alter_info);
 
   /*
     Look if we have to do anything at all.