Fix plugin boolean variables to receive the value "1", not "-1", when they
are set to 1.  Aside from being bizarre, the existing behavior is unportable:
machines where char is unsigned print "255" instead.  Filed upstream at
http://bugs.mysql.com/bug.php?id=59905


diff -up mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_master_enabled_basic.result.p10 mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_master_enabled_basic.result
--- mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_master_enabled_basic.result.p10	2012-08-29 10:50:47.000000000 +0200
+++ mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_master_enabled_basic.result	2012-12-06 14:20:53.078755855 +0100
@@ -45,7 +45,7 @@ set session rpl_semi_sync_master_enabled
 ERROR HY000: Variable 'rpl_semi_sync_master_enabled' is a GLOBAL variable and should be set with SET GLOBAL
 select @@global.rpl_semi_sync_master_enabled;
 @@global.rpl_semi_sync_master_enabled
--1
+1
 select @@session.rpl_semi_sync_master_enabled;
 ERROR HY000: Variable 'rpl_semi_sync_master_enabled' is a GLOBAL variable
 show global variables like 'rpl_semi_sync_master_enabled';
diff -up mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_slave_enabled_basic.result.p10 mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_slave_enabled_basic.result
--- mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_slave_enabled_basic.result.p10	2012-08-29 10:50:47.000000000 +0200
+++ mysql-5.5.28/mysql-test/suite/sys_vars/r/rpl_semi_sync_slave_enabled_basic.result	2012-12-06 14:20:53.078755855 +0100
@@ -45,7 +45,7 @@ set session rpl_semi_sync_slave_enabled=
 ERROR HY000: Variable 'rpl_semi_sync_slave_enabled' is a GLOBAL variable and should be set with SET GLOBAL
 select @@global.rpl_semi_sync_slave_enabled;
 @@global.rpl_semi_sync_slave_enabled
--1
+1
 select @@session.rpl_semi_sync_slave_enabled;
 ERROR HY000: Variable 'rpl_semi_sync_slave_enabled' is a GLOBAL variable
 show global variables like 'rpl_semi_sync_slave_enabled';
diff -up mysql-5.5.28/sql/sql_plugin.cc.p10 mysql-5.5.28/sql/sql_plugin.cc
--- mysql-5.5.28/sql/sql_plugin.cc.p10	2012-08-29 10:50:46.000000000 +0200
+++ mysql-5.5.28/sql/sql_plugin.cc	2012-12-06 14:20:53.078755855 +0100
@@ -2094,7 +2094,7 @@ static int check_func_bool(THD *thd, str
       goto err;
     result= (int) tmp;
   }
-  *(my_bool *) save= -result;
+  *(my_bool *) save= result ? true : false;
   return 0;
 err:
   return 1;