WL#3915 : (NDB) master's cols > slave

Patch corrects minor test anomolies and build warnings.

mysql-test/extra/rpl_tests/rpl_extraMaster_Col.test

@@ -99,7 +99,7 @@ connection master;
 
 #connection slave;
    sync_slave_with_master;
---replace_column 1 # 7 # 8 # 9 # 22 # 23 # 33 #
+--replace_column 1 # 4 # 7 # 8 # 9 # 22 # 23 # 33 #
 --query_vertical show slave status;
    select * from t1 order by f3;
 
@@ -373,7 +373,7 @@ connection master;
    select * from t31;
 
 --replace_result $MASTER_MYPORT MASTER_PORT
---replace_column 1 # 7 # 8 # 9 # 22 # 23 # 33 #
+--replace_column 1 # 4 # 7 # 8 # 9 # 22 # 23 # 33 #
 --query_vertical show slave status;
 
 #### Clean Up ####

sql/field.cc

@@ -6404,7 +6404,8 @@ const char *Field_string::unpack(char *to,
 {
   uint from_len= param_data & 0x00ff;                 // length.
   uint length= 0;
-  uint f_length= (from_len < field_length) ? from_len : field_length;
+  uint f_length;
+  f_length= (from_len < field_length) ? from_len : field_length;
   DBUG_ASSERT(f_length <= 255);
   length= (uint) *from++;
   bitmap_set_bit(table->write_set,field_index);