Merge mysql.com:/usr_rh9/home/elkin.rh9/MySQL/BARE/mysql-5.0

into  mysql.com:/usr_rh9/home/elkin.rh9/MySQL/Merge/5.0

mysql-test/r/func_if.result

@@ -121,3 +121,10 @@ a	NULLIF(a,'')
 NULL	NULL
 	NULL
 DROP TABLE t1;
+create table t1 (f1 int, f2 int);
+insert into t1 values(1,1),(0,0);
+select f1, f2, if(f1, 40.0, 5.00) from t1 group by f1 order by f2;
+f1	f2	if(f1, 40.0, 5.00)
+0	0	5.00
+1	1	40.00
+drop table t1;

mysql-test/t/func_if.test

@@ -89,3 +89,11 @@ SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
 DROP TABLE t1;
 
 # End of 4.1 tests
+
+#
+# Bug #16272 IF function with decimal args can produce wrong result
+#
+create table t1 (f1 int, f2 int);
+insert into t1 values(1,1),(0,0);
+select f1, f2, if(f1, 40.0, 5.00) from t1 group by f1 order by f2;
+drop table t1;

sql/item_cmpfunc.cc

@@ -1383,7 +1383,8 @@ Item_func_if::fix_length_and_dec()
   max_length=
     (cached_result_type == DECIMAL_RESULT || cached_result_type == INT_RESULT) ?
     (max(args[1]->max_length - args[1]->decimals,
-         args[2]->max_length - args[2]->decimals) + decimals) :
+         args[2]->max_length - args[2]->decimals) + decimals +
+         (unsigned_flag ? 0 : 1) ) :
     max(args[1]->max_length, args[2]->max_length);
 }
 

sql/sql_select.cc

@@ -12746,11 +12746,12 @@ calc_group_buffer(JOIN *join,ORDER *group)
     Field *field= group_item->get_tmp_table_field();
     if (field)
     {
-      if (field->type() == FIELD_TYPE_BLOB)
+      enum_field_types type;
+      if ((type= field->type()) == FIELD_TYPE_BLOB)
 	key_length+=MAX_BLOB_WIDTH;		// Can't be used as a key
-      else if (field->type() == MYSQL_TYPE_VARCHAR)
+      else if (type == MYSQL_TYPE_VARCHAR || type == MYSQL_TYPE_VAR_STRING)
         key_length+= field->field_length + HA_KEY_BLOB_LENGTH;
-      else if (field->type() == FIELD_TYPE_BIT)
+      else if (type == FIELD_TYPE_BIT)
       {
         /* Bit is usually stored as a longlong key for group fields */
         key_length+= 8;                         // Big enough