Changing the default of libmysqlclient : it's now NO reconnection.

All our programs which use mysql_real_connect() and mysql_connect() are updated accordingly, though I have deliberately
made mysqlimport not reconnect anymore (already true for mysqldump >= 4.1.8).
All Connector devs have been warned about the change I'm doing here - which was agreed with Monty,
and fixes BUG#2555.


VC++Files/libmysqltest/mytest.c:
  explicit mention of reconnect (no behaviour change)
VC++Files/mysqlmanager/mysqlmanagerview.cpp:
  explicit mention of reconnect (no behaviour change)
VC++Files/test1/mysql_thr.c:
  explicit mention of reconnect (no behaviour change)
VC++Files/winmysqladmin/main.cpp:
  explicit mention of reconnect (no behaviour change)
client/mysql.cc:
  explicit mention of reconnect if embedded (no behaviour change)
client/mysqladmin.cc:
  explicit mention of reconnect (no behaviour change)
client/mysqlbinlog.cc:
  explicit mention of reconnect (no behaviour change)
client/mysqlcheck.c:
  explicit mention of reconnect (no behaviour change)
client/mysqlimport.c:
  explicit mention of NO reconnect (behaviour change). As most time is passed in LOAD DATA INFILE,
  and as it does not make sense to reconnect after a partly failed LOAD... And as mysqlimport sometimes
  does LOCK TABLES where we mustn't reconnect...
client/mysqlshow.c:
  explicit mention of reconnect (no behaviour change)
client/mysqltest.c:
  explicit mention of reconnect (no behaviour change).
  Normally we should not reconnect (it's not good to have silent reconnection in the middle of a test),
  but 5.0 is too touchy to change it now. I'm marking it TODO.
libmysql/libmysql.c:
  explicit mention of reconnect (no behaviour change)
libmysqld/examples/builder-sample/emb_samples.cpp:
  explicit mention of reconnect (no behaviour change)
ndb/test/ndbapi/flex_bench_mysql.cpp:
  explicit mention of reconnect (no behaviour change)
ndb/tools/restore/consumer_restorem.cpp:
  explicit mention of reconnect (no behaviour change)
sql-common/client.c:
  Changing the default of libmysqlclient : it's now NO reconnection.
sql/repl_failsafe.cc:
  explicit mention of reconnect (no behaviour change)
sql/slave.cc:
  explicit mention of reconnect (no behaviour change)
tests/client_test.c:
  explicit mention of reconnect (no behaviour change)
tests/connect_test.c:
  explicit mention of reconnect (no behaviour change)
tests/deadlock_test.c:
  explicit mention of reconnect (no behaviour change)
tests/insert_test.c:
  explicit mention of reconnect (no behaviour change)
tests/list_test.c:
  explicit mention of reconnect (no behaviour change)
tests/select_test.c:
  explicit mention of reconnect (no behaviour change)
tests/showdb_test.c:
  explicit mention of reconnect (no behaviour change)
tests/ssl_test.c:
  explicit mention of reconnect (no behaviour change)
tests/thread_test.c:
  explicit mention of reconnect (no behaviour change)
tools/mysqlmanager.c:
  explicit mention of reconnect (no behaviour change)

1 files changed, 18 insertions, 1 deletions

diff --git a/sql-common/client.c b/sql-common/client.c
index aa50b9fe27b..fd65ed01462 100644
--- a/sql-common/client.c
+++ b/sql-common/client.c
@@ -1587,8 +1587,24 @@ CLI_MYSQL_REAL_CONNECT(MYSQL *mysql,const char *host, const char *user,
     port=mysql->options.port;
   if (!unix_socket)
     unix_socket=mysql->options.unix_socket;
+  
+  /*
+    By default we don't reconnect because it could silently corrupt data (after
+    reconnection you potentially lose table locks, user variables, session
+    variables (transactions but they are specifically dealt with in
+    mysql_reconnect()).
+    This is a change: < 5.0.3 mysql->reconnect was set to 1 by default.
+    How this change impacts existing apps:
+    - existing apps which relyed on the default will see a behaviour change;
+    they will have to set reconnect=1 after mysql_real_connect().
+    - existing apps which explicitely asked for reconnection (the only way they
+    could do it was by setting mysql.reconnect to 1 after mysql_real_connect())
+    will not see a behaviour change.
+    - existing apps which explicitely asked for no reconnection
+    (mysql.reconnect=0) will not see a behaviour change.
+  */
+  mysql->reconnect= 0;
 
-  mysql->reconnect=1;				/* Reconnect as default */
   mysql->server_status=SERVER_STATUS_AUTOCOMMIT;
 
   /*
@@ -2161,6 +2177,7 @@ my_bool mysql_reconnect(MYSQL *mysql)
     strmov(mysql->net.sqlstate, tmp_mysql.net.sqlstate);
     DBUG_RETURN(1);
   }
+  tmp_mysql.reconnect= 1;
   tmp_mysql.free_me= mysql->free_me;
   /* Don't free options as these are now used in tmp_mysql */
   bzero((char*) &mysql->options,sizeof(mysql->options));