BUG #4838: Database corruption after btree_gin index creation

The following bug has been logged online:

Bug reference: 4838
Logged by: Daniele Bortoluzzi
Email address: bortoluz(at)gmail(dot)com
PostgreSQL version: 8.4beta2
Operating system: Linux amd64 2.6.24 (Debian 4.0)
Description: Database corruption after btree_gin index creation
Details:

I am testing this db
I created a multicolumn GIN index with btree_gin functionality (fulltext
column + timestamp). After creating the index the db segfaulted:

LOG: server process (PID 14195) was terminated by signal 11: Segmentation
fault
LOG: terminating any other active server processes
WARNING: terminating connection because of crash of another server process
DETAIL: The postmaster has commanded this server process to roll back the
current transaction and exit, because another server process exited
abnormally and
possibly corrupted shared memory.
HINT: In a moment you should be able to reconnect to the database and
repeat your command.

The WARNING-DETAIL-HINT messages repeated 4 times, then postgres restarted:

LOG: all server processes terminated; reinitializing
LOG: database system was interrupted; last known up at 2009-06-04 12:47:19
CEST
LOG: database system was not properly shut down; automatic recovery in
progress
LOG: redo starts at 2/778687D0
LOG: record with zero length at 2/779392A8
LOG: redo done at 2/77938E20
LOG: last completed transaction was at log time 2009-06-04
12:47:35.55392+02
LOG: autovacuum launcher started
LOG: database system is ready to accept connections

but segfaulted 2 times more.

Then I launched a VACUUM FULL ANALYZE, no segmentation faults, it completed
succesfully, but now it throws this error:

ERROR: tuple offset out of range: 48090

or

ERROR: tuple offset out of range: 0

when doing fulltext queries.

I was using postgres 8.4devel (SVN revision 28901) happily...