If a line starting with '--' has been removed, it is not colored red on the merge proposal page as it should be. https://code.launchpad.net/~stub/launchpad/pending-db-changes/+merge/23116 for an example.
=== removed file 'database/replication/authdb_create.sql'
111 --- database/replication/authdb_create.sql 2010-03-30 05:51:30 +0000
112 +++ database/replication/authdb_create.sql 1970-01-01 00:00:00 +0000
113 @@ -1,885 +0,0 @@
114 --- Copyright 2009 Canonical Ltd. This software is licensed under the
115 --- GNU Affero General Public License version 3 (see the file LICENSE).
116 -
117 --- Generated by:
118 --- pg_dump --format=p --schema-only --no-owner --no-privileges \
119 --- --table=Account --table=AccountPassword --table=AuthToken \
120 --- --table=EmailAddress --table=OpenIDAssociation \
121 --- --table=OpenIDAuthorization --table=OpenIDNonce \
122 --- --table=OpenIDRPSummary --table=ValidPersonCache \
123 --- --table=ValidPersonOrTeamCache launchpad_prod_4
124 -
125 ---
126 --- PostgreSQL database dump
127 ---
So, uh, how do I tell when this code has gone live, at least on 'edge'?