Update pg_upgrade comment on missing 'postgres' database.

diff --git a/contrib/pg_upgrade/relfilenode.c b/contrib/pg_upgrade/relfilenode.c
index ad893be1c7fa240180b2cad519806516050f886b..382588f19165981f9fa5b4d62f3ade873dbe4e58 100644 (file)
--- a/contrib/pg_upgrade/relfilenode.c
+++ b/contrib/pg_upgrade/relfilenode.c
@@ -52,7 +52,8 @@ transfer_all_new_dbs(DbInfoArr *old_db_arr,
 
                /*
                 *      Advance past any databases that exist in the new cluster
-                *      but not in the old, e.g. "postgres".
+                *      but not in the old, e.g. "postgres".  (The user might
+                *      have removed the 'postgres' database from the old cluster.)
                 */
                while (strcmp(old_db->db_name, new_db->db_name) != 0 &&
                           new_dbnum < new_db_arr->ndbs)