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

@@ -91,6 +91,7 @@ main( int argc, char * argv[] )
        mysql_real_connect( myData, NULL, NULL, NULL, NULL, MYSQL_PORT,
 			   NULL, 0 ) )
     {
+      myData->reconnect= 1;
       if ( mysql_select_db( myData, szDB ) < 0 ) {
 	printf( "Can't select the %s database !\n", szDB ) ;
 	mysql_close( myData ) ;

VC++Files/mysqlmanager/mysqlmanagerview.cpp

@@ -551,6 +551,7 @@ void CMySqlManagerView::OnDblclk(NMHDR* pNMHDR, LRESULT* pResult)
 					PostMessage(WM_COMMAND,IDM_TOOLS_SERVER_PROPERTIES);
                return;
             }
+            mysql.reconnect= 1;
             if (!(result=mysql_list_processes(&mysql)))
             {
                return;
@@ -576,6 +577,7 @@ void CMySqlManagerView::OnDblclk(NMHDR* pNMHDR, LRESULT* pResult)
                                     );
                return;
             }
+            mysql.reconnect= 1;
             if (!(result=mysql_list_dbs(&mysql,0)))
             {
             }
@@ -603,6 +605,7 @@ void CMySqlManagerView::OnDblclk(NMHDR* pNMHDR, LRESULT* pResult)
                                     );
                return;
             }
+            mysql.reconnect= 1;
             CResourceDatabase* pRes = (CResourceDatabase*) pResource;
             CString strDB = pResource->GetDisplayName();
             strDB.TrimRight();
@@ -641,6 +644,7 @@ void CMySqlManagerView::OnDblclk(NMHDR* pNMHDR, LRESULT* pResult)
                                     );
                return;
             }
+            mysql.reconnect= 1;
             HTREEITEM hParent = m_pTree->GetParentItem(hItem);
             memset( &item, 0, sizeof(TV_ITEM) );
             item.hItem = hParent;
@@ -714,6 +718,7 @@ void CMySqlManagerView::OnRefresh()
                {
                   return;
                }
+               mysql.reconnect= 1;
                memset( &item, 0, sizeof(TV_ITEM) );
                item.hItem = hParent;
                item.mask = TVIF_TEXT | TVIF_HANDLE | TVIF_CHILDREN | TVIF_PARAM ;

VC++Files/test1/mysql_thr.c

@@ -167,6 +167,7 @@ pthread_handler_decl(test_thread,arg)
     perror("");
     goto end;
   }
+  mysql.reconnect= 1;
   if (mysql_query(&mysql,"select 1") < 0)
   {
     fprintf(stderr,"Query failed (%s)\n",mysql_error(&mysql));

VC++Files/winmysqladmin/main.cpp

@@ -1337,6 +1337,7 @@ void __fastcall TForm1::IsMySQLInit(void)
           }
 
         }
+       MySQL->reconnect= 1;
 
       }
 
@@ -1348,6 +1349,7 @@ void __fastcall TForm1::IsMySQLInit(void)
       MySQL = mysql_init(MySQL);
       if(mysql_real_connect(MySQL,host,user,password , 0, 0, NULL, 0))
       IsConnect = true;
+      MySQL->reconnect= 1;
     }
   }
 }

client/mysql.cc

@@ -2792,6 +2792,8 @@ sql_real_connect(char *host,char *database,char *user,char *password,
   connected=1;
 #ifndef EMBEDDED_LIBRARY
   mysql.reconnect=info_flag ? 1 : 0; // We want to know if this happens
+#else
+  mysql.reconnect= 1;
 #endif
 #ifdef HAVE_READLINE
   build_completion_hash(rehash, 1);

client/mysqladmin.cc

@@ -425,6 +425,7 @@ static my_bool sql_connect(MYSQL *mysql, uint wait)
     if (mysql_real_connect(mysql,host,user,opt_password,NullS,tcp_port,
 			   unix_port, 0))
     {
+      mysql->reconnect= 1;
       if (info)
       {
 	fputs("\n",stderr);

client/mysqlbinlog.cc

@@ -753,6 +753,7 @@ static MYSQL* safe_connect()
     mysql_options(local_mysql, MYSQL_OPT_PROTOCOL, (char*) &opt_protocol);
   if (!mysql_real_connect(local_mysql, host, user, pass, 0, port, sock, 0))
     die("failed on connect: %s", mysql_error(local_mysql));
+  local_mysql->reconnect= 1;
 
   return local_mysql;
 }

client/mysqlcheck.c

@@ -628,6 +628,7 @@ static int dbConnect(char *host, char *user, char *passwd)
     DBerror(&mysql_connection, "when trying to connect");
     return 1;
   }
+  mysql_connection.reconnect= 1;
   return 0;
 } /* dbConnect */
 

client/mysqlimport.c

@@ -388,6 +388,7 @@ static MYSQL *db_connect(char *host, char *database, char *user, char *passwd)
     ignore_errors=0;	  /* NO RETURN FROM db_error */
     db_error(&mysql_connection);
   }
+  mysql_connection.reconnect= 0;
   if (verbose)
     fprintf(stdout, "Selecting database %s\n", database);
   if (mysql_select_db(sock, database))

client/mysqlshow.c

@@ -125,6 +125,7 @@ int main(int argc, char **argv)
     fprintf(stderr,"%s: %s\n",my_progname,mysql_error(&mysql));
     exit(1);
   }
+  mysql.reconnect= 1;
 
   switch (argc)
   {

client/mysqltest.c

@@ -1627,6 +1627,7 @@ int safe_connect(MYSQL* con, const char* host, const char* user,
     }
     sleep(CON_RETRY_SLEEP);
   }
+  con->reconnect= 1; /* TODO: change this to 0 in future versions */
   return con_error;
 }
 

libmysql/libmysql.c

@@ -317,6 +317,7 @@ my_bool STDCALL mysql_master_send_query(MYSQL *mysql, const char *q,
   DBUG_ENTER("mysql_master_send_query");
   if (!master->net.vio && !mysql_real_connect(master,0,0,0,0,0,0,0))
     DBUG_RETURN(1);
+  master->reconnect= 1;
   mysql->last_used_con = master;
   DBUG_RETURN(simple_command(master, COM_QUERY, q, length, 1));
 }
@@ -351,6 +352,7 @@ my_bool STDCALL mysql_slave_send_query(MYSQL *mysql, const char *q,
   if (!slave_to_use->net.vio && !mysql_real_connect(slave_to_use, 0,0,0,
 						    0,0,0,0))
     DBUG_RETURN(1);
+  slave_to_use->reconnect= 1;
   DBUG_RETURN(simple_command(slave_to_use, COM_QUERY, q, length, 1));
 }
 
@@ -448,6 +450,7 @@ static my_bool get_slaves_from_master(MYSQL* mysql)
     expand_error(mysql, CR_PROBE_MASTER_CONNECT);
     DBUG_RETURN(1);
   }
+  mysql->reconnect= 1;
 
   if (mysql_query(mysql, "SHOW SLAVE HOSTS") ||
       !(res = mysql_store_result(mysql)))
@@ -615,6 +618,7 @@ mysql_connect(MYSQL *mysql,const char *host,
       if (mysql->free_me)
 	my_free((gptr) mysql,MYF(0));
     }
+    mysql->reconnect= 1;
     DBUG_RETURN(res);
   }
 }

libmysqld/examples/builder-sample/emb_samples.cpp

@@ -109,6 +109,7 @@ bool __fastcall TForm1::connect_server()
    ret_value = true;
    is_server_started = true;
   }
+  MySQL->reconnect= 1;
   return ret_value;
 }
 //---------------------------------------------------------------------------

ndb/test/ndbapi/flex_bench_mysql.cpp

@@ -397,6 +397,7 @@ NDB_COMMAND(flexBench, "flexBench", "flexBench", "flexbench", 65535)
         ndbout << "Connect failed" <<endl;
         returnValue = NDBT_FAILED;
       }
+      mysql.reconnect= 1;
     }
     if(returnValue == NDBT_OK){
       mysql_set_server_option(&mysql, MYSQL_OPTION_MULTI_STATEMENTS_ON);
@@ -712,6 +713,7 @@ static void* flexBenchThread(void* pArg)
       ndbout << "failed" << endl;
       NdbThread_Exit(0) ;
     }
+    mysql.reconnect= 1;
     ndbout << "ok" << endl;
 
     int r;

ndb/tools/restore/consumer_restorem.cpp

@@ -80,6 +80,7 @@ BackupRestore::init()
 	ndbout_c("Connect failed: %s", mysql_error(&mysql));
 	returnValue = false;
       }
+      mysql.reconnect= 1;
       ndbout << "Connected to MySQL!!!" <<endl;
     }
 

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));

sql/repl_failsafe.cc

@@ -709,6 +709,7 @@ int connect_to_master(THD *thd, MYSQL* mysql, MASTER_INFO* mi)
   if (!mysql_real_connect(mysql, mi->host, mi->user, mi->password, 0,
 			mi->port, 0, 0))
     DBUG_RETURN(1);
+  mysql->reconnect= 1;
   DBUG_RETURN(0);
 }
 

sql/slave.cc

@@ -4394,6 +4394,7 @@ replication resumed in log '%s' at position %s", mi->user,
     thd->set_active_vio(mysql->net.vio);
 #endif      
   }
+  mysql->reconnect= 1;
   DBUG_PRINT("exit",("slave_was_killed: %d", slave_was_killed));
   DBUG_RETURN(slave_was_killed);
 }

tests/client_test.c

@@ -243,6 +243,7 @@ static void client_connect()
     fprintf(stdout, "\n Check the connection options using --help or -?\n");
     exit(1);
   }
+  mysql->reconnect= 1;
 
   if (!opt_silent)
     fprintf(stdout, " OK");
@@ -1050,6 +1051,7 @@ static my_bool thread_query(char *query)
     error= 1;
     goto end;
   }
+  l_mysql->reconnect= 1;
   if (mysql_query(l_mysql, (char *)query))
   {
      fprintf(stderr, "Query failed (%s)\n", mysql_error(l_mysql));
@@ -4474,6 +4476,7 @@ static void test_stmt_close()
     myerror("connection failed");
     exit(1);
   }
+  lmysql->reconnect= 1;
   if (!opt_silent)
     fprintf(stdout, " OK");
 
@@ -5365,6 +5368,7 @@ DROP TABLE IF EXISTS test_multi_tab";
     fprintf(stdout, "\n connection failed(%s)", mysql_error(mysql_local));
     exit(1);
   }
+  mysql_local->reconnect= 1;
 
   rc= mysql_query(mysql_local, query);
   myquery(rc);
@@ -5473,6 +5477,7 @@ static void test_prepare_multi_statements()
     fprintf(stderr, "\n connection failed(%s)", mysql_error(mysql_local));
     exit(1);
   }
+  mysql_local->reconnect= 1;
   strmov(query, "select 1; select 'another value'");
   stmt= mysql_simple_prepare(mysql_local, query);
   check_stmt_r(stmt);
@@ -7004,6 +7009,7 @@ static void test_prepare_grant()
       mysql_close(lmysql);
       exit(1);
     }
+    lmysql->reconnect= 1;
     if (!opt_silent)
       fprintf(stdout, " OK");
 
@@ -7439,6 +7445,7 @@ static void test_drop_temp()
       mysql_close(lmysql);
       exit(1);
     }
+    lmysql->reconnect= 1;
     if (!opt_silent)
       fprintf(stdout, " OK");
 

tests/connect_test.c

@@ -46,6 +46,7 @@ int main(int argc, char **argv)
     perror("");
     exit(1);
   }
+  sock->reconnect= 1;
 
   if (mysql_select_db(sock,"test"))
   {

tests/deadlock_test.c

@@ -227,6 +227,7 @@ int main()
      !mysql_real_connect(&sel, host, user, pass, db, 0,0,0 ) ||
      !mysql_real_connect(&del_ins, host, user, pass, db, 0,0,0 ))
     die("Error in mysql_real_connect(): %s", mysql_error(&lock));
+  lock.reconnect= sel.reconnect= del_ins.reconnect= 1;
 
   permute(order, num_queries);
   printf("count = %d\n", count);

tests/insert_test.c

@@ -40,6 +40,7 @@ int main(int argc, char **argv)
     perror("");
     exit(1);
   }
+  mysql.reconnect= 1;
 
   num = atoi(argv[2]);
   count = 0;

tests/list_test.c

@@ -43,6 +43,7 @@ int main(int argc, char **argv)
     perror("");
     exit(1);
   }
+  mysql.reconnect= 1;
 
   if (mysql_select_db(sock,argv[1]) < 0)
   {

tests/select_test.c

@@ -44,6 +44,7 @@ int main(int argc, char **argv)
     perror("");
     exit(1);
   }
+  mysql.reconnect= 1;
 
   count = 0;
   num = atoi(argv[2]);

tests/showdb_test.c

@@ -45,6 +45,7 @@ int main(int argc, char **argv)
     perror("");
     exit(1);
   }
+  mysql.reconnect= 1;
 
   count = 0;
   num = atoi(argv[2]);

tests/ssl_test.c

@@ -51,6 +51,7 @@ int main(int argc, char **argv)
     perror("");
     exit(1);
   }
+  mysql.reconnect= 1;
   count = 0;
   num = atoi(argv[2]);
   while (count < num)

tests/thread_test.c

@@ -55,6 +55,7 @@ unsigned __stdcall test_thread(void *arg __attribute__((unused)))
     perror("");
     goto end;
   }
+  mysql.reconnect= 1;
   if (verbose) { putchar('*'); fflush(stdout); }
   for (count=0 ; count < number_of_tests ; count++)
   {

tools/mysqlmanager.c

@@ -877,7 +877,10 @@ static void manager_exec_connect(struct manager_exec* e)
   {
     if (mysql_real_connect(&e->mysql,e->con_host,e->con_user,e->con_pass,0,
 			   e->con_port,e->con_sock,0))
+    {
+      e->mysql.reconnect= 1;
       return;
+    }
     sleep(1);
   }
   e->error="Could not connect to MySQL server withing the number of tries";