bat.inplace() strange exception

Hello,

considering the following interaction

$ mclient -lmal -d test
Welcome to mclient, the MonetDB interactive terminal (unreleased)
Type \q to quit, \? for a list of available commands
mal>sql.init();
mal>_mvc := sql.mvc();
mal>abat:bat[:int,:int] := bat.new(:int, :int);
mal>bat.insert(abat, 1, 4);
mal>bat.insert(abat, 1, 4);
mal>bat.insert(abat, 1, 1);
mal>bat.insert(abat, 1, 1);
mal>bat.insert(abat, 0, 4);
mal>bat.inplace(abat, 0, 5);
MAPI  = (monetdb) /tmp/.s.monetdb.50000
ACTION= read_line
QUERY = bat.inplace(abat, 0, 5);
ERROR = !Connection terminated

Is this a bug or not?

The log of merovingian is the following:

2011-12-07 13:01:51 ERR test[15564]: mserver5:
../../MonetDB/gdk/gdk_bat.mx:1917: void_inplace: Assertion `b->H->type
== 0' failed.
2011-12-07 13:01:51 MSG merovingian[14343]: database 'test' (15564)
was killed by signal SIGABRT