Spamassassin fails to escape backslashes for latest postgres input syntax

Using:
- Spamassassin
- Postgres
- DBI
- DBD:Pg

I get the following error when attempting to sa-learn --restore:

[24850] dbg: bayes: tok_get: SQL error: ERROR: invalid input syntax for type bytea
[24850] dbg: bayes: _put_token: SQL error: ERROR: invalid input syntax for type bytea
[24850] dbg: bayes: error inserting token for line: t 1 0 1240037056 0178865c33

When run with DBI_TRACE=3, I get the following output:

    -> execute for DBD::Pg::st (DBI::st=HASH(0x99b9c24)~0x99c6f60 '8' '.^M<E4>\<8C>') thr#
814e008
dbdpg: ERROR: invalid input syntax for type bytea

The problem is that Postgres 8.3 is expecting the backslash to be escaped if it represents a literal backslash. The following patch seems to resolve the problem, and I think it is backward-compatible, though not necessarily compatible with SQLite or MySql:

--- spamassassin-3.2.3-0.volatile/lib/Mail/SpamAssassin/BayesStore/SQL.pm 2009-05-12 14:58:28.000000000 +0000
+++ spamassassin-fixed/lib/Mail/SpamAssassin/BayesStore/SQL.pm 2009-05-12 14:07:21.000000
000 +0000
@@ -1522,6 +1522,8 @@
       else {
        # turn unpacked binary token back into binary value
        $token = pack("H*",$token);
+ # Escape backslashes for DB's benefit
+ $token =~ s/\\/\\0134/g;
       }

       unless ($self->_put_token($token, $spam_count, $ham_count, $atime)) {