Adding index on a merged table "breaks" merge functionality

[Orna Weisman]

Hi

I created two base myIsam tables with two columns and no indexes and a merge table for these two as :

create table test_merge...
...
ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST
UNION=(`test1`,`test2`)

All works fine until I added an index on test1.
Once I did that all inserts into the merge table were not added to test1, but were added to the test_merge table only - like it is a regular table and not a merge table.

However - if I dropped the merge table and recreated it, then all subsequent inserts were inserted correctly to the base table ( even though the index was still there on test1 ).

Is this an expected behavior ?
mysql version is 5.0.27