restrict edit to positive id

edit 0 is accepted in the org.gnome.Hamster.WindowServer
for backward compatibility reasons only.
Accept only strictly positive id for the cli edit.

src/hamster-cli.py

@@ -496,7 +496,9 @@ def version(self):
                 assert len(args.action_args) == 1, (
                        "edit requires exactly one argument, got {}"
                        .format(args.action_args))
-                action_data = glib.Variant.new_int32(int(args.action_args[0]))
+                id_ = int(args.action_args[0])
+                assert id_ > 0, "received non-positive id : {}".format(id_)
+                action_data = glib.Variant.new_int32(id_)
             else:
                 action_data = None
             app.activate_action(action, action_data)

src/hamster-windows-service.py

@@ -53,12 +53,15 @@ def _open_window(self, name):
         subprocess.run(cmd, shell=True)
 
     @dbus.service.method("org.gnome.Hamster.WindowServer", in_signature='i')
-    def edit(self, id=0):
+    def edit(self, id):
         """Edit fact, given its id (int) in the database.
 
         For backward compatibility, if id is 0, create a brand new fact.
         """
-        self._open_window("edit {}".format(id))
+        if id:
+            self._open_window("edit {}".format(id))
+        else:
+            self._open_window("add")
 
     @dbus.service.method("org.gnome.Hamster.WindowServer")
     def overview(self):