From bea551092d125eccc0cca8ccb89ba4ebcf8ff79b Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Tue, 13 Jun 2017 15:27:41 +0300
Subject: [PATCH] MXS-1278: Change modes when 'set sql_mode=' is encountered.

The initial setting of sql_mode affects how MaxScale initially
behaves with respect to autocommit.

When 'set sql_mode=[default|oracle];" is encountered, the query
classifier and autocommit modes are adjusted accordingly.
---
 Documentation/Getting-Started/Configuration-Guide.md      | 8 ++++++++
 server/core/session.c                                     | 6 ++++++
 server/modules/protocol/MySQL/MySQLClient/mysql_client.cc | 2 ++
 3 files changed, 16 insertions(+)

diff --git a/Documentation/Getting-Started/Configuration-Guide.md b/Documentation/Getting-Started/Configuration-Guide.md
index 6246b93d3..a31823a0a 100644
--- a/Documentation/Getting-Started/Configuration-Guide.md
+++ b/Documentation/Getting-Started/Configuration-Guide.md
@@ -534,6 +534,9 @@ sql_mode=oracle
 
 The default value is `default`.
 
+**NOTE** If `sql_mode` is set to `oracle`, then MaxScale will also assume
+that `autocommit` initially is off.
+
 At runtime, MariaDB MaxScale will recognize statements like
 ```
 set sql_mode=oracle;
@@ -544,6 +547,11 @@ set sql_mode=default;
 ```
 and change mode accordingly.
 
+**NOTE** If `set sql_mode=oracle;` is encountered, then MaxScale will also
+behave as if `autocommit` had been turned off and conversely, if
+`set sql_mode=default;` is encountered, then MaxScale will also behave
+as if `autocommit` had been turned on.
+
 Note that MariaDB MaxScale is **not** explicitly aware of the sql mode of
 the server, so the value of `sql_mode` should reflect the sql mode used
 when the server is started.
diff --git a/server/core/session.c b/server/core/session.c
index fff7f9832..2403532b2 100644
--- a/server/core/session.c
+++ b/server/core/session.c
@@ -112,6 +112,12 @@ session_alloc(SERVICE *service, DCB *client_dcb)
     session->stats.connect = time(0);
     session->stmt.buffer = NULL;
     session->stmt.target = NULL;
+
+    MXS_CONFIG *config = config_get_global_options();
+    // If MaxScale is running in Oracle mode, then autocommit needs to
+    // initially be off.
+    bool autocommit = (config->qc_sql_mode == QC_SQL_MODE_ORACLE) ? false : true;
+    session_set_autocommit(session, autocommit);
     /*<
      * Associate the session to the client DCB and set the reference count on
      * the session to indicate that there is a single reference to the
diff --git a/server/modules/protocol/MySQL/MySQLClient/mysql_client.cc b/server/modules/protocol/MySQL/MySQLClient/mysql_client.cc
index da8b69e5a..6cf503cc4 100644
--- a/server/modules/protocol/MySQL/MySQLClient/mysql_client.cc
+++ b/server/modules/protocol/MySQL/MySQLClient/mysql_client.cc
@@ -888,10 +888,12 @@ void set_qc_mode(MXS_SESSION* session, GWBUF** read_buffer)
         switch (sql_mode)
         {
         case SetSqlModeParser::ORACLE:
+            session_set_autocommit(session, false);
             session->client_protocol_data = QC_SQL_MODE_ORACLE;
             break;
 
         case SetSqlModeParser::DEFAULT:
+            session_set_autocommit(session, true);
             session->client_protocol_data = QC_SQL_MODE_DEFAULT;
             break;