Adding regular column to COMPACT tables without clustering columns should trigger an InvalidRequestException

x@cqlsh:xuser> CREATE TABLE xuser.employee(emp_id int PRIMARY KEY,emp_name text, emp_city text, emp_sal varint, emp_phone varint ) WITH  COMPACT STORAGE;
x@cqlsh:xuser> desc table xuser.employee ;

CREATE TABLE xuser.employee (
emp_id int PRIMARY KEY,
emp_city text,
emp_name text,
emp_phone varint,
emp_sal varint
) WITH COMPACT STORAGE
AND bloom_filter_fp_chance = 0.01
AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}
AND comment = ''
AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}
AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}
AND crc_check_chance = 1.0
AND dclocal_read_repair_chance = 0.1
AND default_time_to_live = 0
AND gc_grace_seconds = 864000
AND max_index_interval = 2048
AND memtable_flush_period_in_ms = 0
AND min_index_interval = 128
AND read_repair_chance = 0.0
AND speculative_retry = '99PERCENTILE';

x@cqlsh:xuser>  alter table employee add profile text;
x@cqlsh:xuser> desc table xuser.employee ;

CREATE TABLE xuser.employee (
    emp_id int PRIMARY KEY,
    emp_city text,
    emp_name text,
    emp_phone varint,
    emp_sal varint
) WITH COMPACT STORAGE
    AND bloom_filter_fp_chance = 0.01
    AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}
    AND comment = ''
    AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}
    AND compression = {'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND crc_check_chance = 1.0
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99PERCENTILE';

x@cqlsh:xuser>  alter table employee add profile text;
InvalidRequest: Error from server: code=2200 [Invalid query] message="Invalid column name profile because it conflicts with an existing column"
x@cqlsh:xuser> select emp_name,profile from employee;

 emp_name | profile
----------+---------

(0 rows)
x@cqlsh:xuser>

x@cqlsh:xuser> INSERT INTO employee (emp_id , emp_city , emp_name , emp_phone , emp_sal ,profile) VALUES ( 1, 'ggn', 'john', 123456, 50000, 'SE');
InvalidRequest: Error from server: code=2200 [Invalid query] message="Some clustering keys are missing: column1"
x@cqlsh:xuser> INSERT INTO employee (emp_id , emp_city , emp_name , emp_phone , emp_sal ,profile,column1) VALUES ( 1, 'ggn', 'john', 123456, 50000, 'SE',null);
x@cqlsh:xuser> select * from employee;

 emp_id | emp_city | emp_name | emp_phone | emp_sal
--------+----------+----------+-----------+---------

(0 rows)