BUG #5219: Segfault in to_tsvector

The following bug has been logged online:

Bug reference: 5219
Logged by: Kenaniah Cerny
Email address: kenaniah@gmail.com
PostgreSQL version: 8.4.1
Operating system: Centos5.2 -- Linux 2.6.18-92.1.10.el5 #1 SMP i686 athlon
i386 GNU/Linux
Description: Segfault in to_tsvector
Details:

Full backtrace: http://pgsql.privatepaste.com/5411abf8f3

The issue takes place running this query:
http://pgsql.privatepaste.com/35064cbba8

Crash is attributed to this index definition:
CREATE INDEX "anime_titles_idx_name_simple_text" ON "public"."anime_titles"
USING gin ((to_tsvector('simple'::regconfig, name)));

I believe the issue is caused by possibly non-UTF-8 data. Both the server
and the client (a PHP script using PDO's pgsql driver) are using UTF-8. The
string causing this issue is stored in the database in a text field and
looks like this:
http://s801.photobucket.com/albums/yy299/kenaniah972/?action=view&current=is
sue.png

After output into an HTML input field and resubmission through firefox, the
string that is passed through to the DB looks like this:
http://s801.photobucket.com/albums/yy299/kenaniah972/?action=view&current=su
bmitted.png

(The &# characters were manually omitted in submission)

I don't profess to know anything about encodings, but I don't think this is
valid UTF-8 input. I might be wrong. All I do know is that this causes the
to_tsvector part of the gin index to throw a segfault in the insert
statement, rather than returning an invalid UTF-8 input error or just plain
working.