# 
# 
# patch "automate.cc"
#  from [6519694114e5381dce9f2c2d3fe1454f5b5b6f64]
#    to [786b895a5c7dff49030b9280c0e9e03453ce7c3c]
# 
# patch "tests/automate_cert/__driver__.lua"
#  from [5dc754cbcd83fffd23652e6ba521d060d7c759aa]
#    to [21c1631cb67da926ed7fdc1995db5dae2130bb05]
# 
============================================================
--- automate.cc	6519694114e5381dce9f2c2d3fe1454f5b5b6f64
+++ automate.cc	786b895a5c7dff49030b9280c0e9e03453ce7c3c
@@ -1737,11 +1737,16 @@ AUTOMATE(cert, N_("REVISION-ID NAME VALU
 
   cert c;
   revision_id rid(idx(args, 0)());
+
+  transaction_guard guard(app.db);
+  N(app.db.revision_exists(rid),
+    F("no such revision '%s'") % rid);
   make_simple_cert(rid.inner(), cert_name(idx(args, 1)()),
                    cert_value(idx(args, 2)()), app, c);
   revision<cert> rc(c);
   packet_db_writer dbw(app);
   dbw.consume_revision_cert(rc);
+  guard.commit();
 }
 
 // Name: db_set
============================================================
--- tests/automate_cert/__driver__.lua	5dc754cbcd83fffd23652e6ba521d060d7c759aa
+++ tests/automate_cert/__driver__.lua	21c1631cb67da926ed7fdc1995db5dae2130bb05
@@ -17,3 +17,12 @@ check(samefile("expected", "stdout"))
 check(mtn("automate", "certs", base), 0, true, false)
 canonicalize("stdout")
 check(samefile("expected", "stdout"))
+
+-- check edge cases:
+-- wrong number of arguments:
+check(mtn("automate", "cert", base, "asdf"), 1, false, false)
+check(mtn("automate", "cert", base, "testcert", "testvalue", "asdf"), 1, false, false)
+-- nonexistent revision:
+check(mtn("automate", "cert", "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+          "branch", "net.venge.monotone"),
+      1, false, false)