add height flag for upgrade clients tx (cosmos#374)

cmd/tx.go

@@ -145,6 +145,11 @@ func upgradeClientsCmd() *cobra.Command {
 				return err
 			}
 
+			height, err := cmd.Flags().GetInt64(flags.FlagHeight)
+			if err != nil {
+				return err
+			}
+
 			// ensure that keys exist
 			if _, err = c[src].GetAddress(); err != nil {
 				return err
@@ -156,13 +161,13 @@ func upgradeClientsCmd() *cobra.Command {
 			targetChainID := args[1]
 			// send the upgrade message on the targetChainID
 			if src == targetChainID {
-				return c[src].UpgradeClients(c[dst])
+				return c[src].UpgradeClients(c[dst], height)
 			}
 
-			return c[dst].UpgradeClients(c[src])
+			return c[dst].UpgradeClients(c[src], height)
 		},
 	}
-	return cmd
+	return heightFlag(cmd)
 }
 
 func createConnectionCmd() *cobra.Command {

relayer/client-tx.go

@@ -151,15 +151,18 @@ func (c *Chain) UpdateClients(dst *Chain) (err error) {
 }
 
 // UpgradesClients upgrades the client on src after dst chain has undergone an upgrade.
-func (c *Chain) UpgradeClients(dst *Chain) error {
+func (c *Chain) UpgradeClients(dst *Chain, height int64) error {
 	sh, err := NewSyncHeaders(c, dst)
 	if err != nil {
 		return err
 	}
 	if err := sh.Updates(c, dst); err != nil {
 		return err
 	}
-	height := int64(sh.GetHeight(dst.ChainID))
+
+	if height == 0 {
+		height = int64(sh.GetHeight(dst.ChainID))
+	}
 
 	// TODO: construct method of only attempting to get dst header
 	// Note: we explicitly do not check the error since the source