Fix for BUG#13897 "failure to do SET SQL_MODE=N where N is a number > 31" (the...

Fix for BUG#13897 "failure to do SET SQL_MODE=N where N is a number > 31" (the original bug's title isn't the simplest
symptom). sys_var::check_set() was wrong. mysqlbinlog makes use of such SET SQL_MODE=N
(where N is interpreted like if SQL_MODE was a field of type SET), so
this bug affected recovery from binlogs if the server was running with certain SQL_MODE values,
for example the default values on Windows (STRICT_TRANS_TABLES); to work around this bug people
had to edit mysqlbinlog's output.

mysql-test/r/sql_mode.result

@@ -478,4 +478,20 @@ v1	CREATE ALGORITHM=UNDEFINED DEFINER="root"@"localhost" SQL SECURITY DEFINER VI
 create view v2 as select a from t2 where a in (select a from v1);
 drop view v2, v1;
 drop table t1, t2;
+select @@sql_mode;
+@@sql_mode
+ANSI_QUOTES
+set sql_mode=2097152;
+select @@sql_mode;
+@@sql_mode
+STRICT_TRANS_TABLES
+set sql_mode=16384+(65536*4);
+select @@sql_mode;
+@@sql_mode
+REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,NO_TABLE_OPTIONS,ANSI
+set sql_mode=2147483648;
+ERROR 42000: Variable 'sql_mode' can't be set to the value of '2147483648'
+select @@sql_mode;
+@@sql_mode
+REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,NO_TABLE_OPTIONS,ANSI
 SET @@SQL_MODE=@OLD_SQL_MODE;

mysql-test/t/sql_mode.test

@@ -255,4 +255,13 @@ create view v2 as select a from t2 where a in (select a from v1);
 drop view v2, v1;
 drop table t1, t2;
 
+select @@sql_mode;
+set sql_mode=2097152;
+select @@sql_mode;
+set sql_mode=16384+(65536*4);
+select @@sql_mode;
+--error 1231
+set sql_mode=2147483648; # that mode does not exist
+select @@sql_mode;
+
 SET @@SQL_MODE=@OLD_SQL_MODE;

sql/set_var.cc

@@ -1659,7 +1659,12 @@ bool sys_var::check_set(THD *thd, set_var *var, TYPELIB *enum_names)
   else
   {
     ulonglong tmp= var->value->val_int();
-    if (tmp >= enum_names->count)
+   /*
+     For when the enum is made to contain 64 elements, as 1ULL<<64 is
+     undefined, we guard with a "count<64" test.
+   */
+    if (unlikely((tmp >= ((ULL(1)) << enum_names->count)) &&
+                 (enum_names->count < 64)))
     {
       llstr(tmp, buff);
       goto err;