From d2ef9582b0d4ae9fc48feb6698cabe59b540492c Mon Sep 17 00:00:00 2001
From: Mike Naberezny <mike@naberezny.com>
Date: Sat, 23 Nov 2013 16:33:00 -0800
Subject: [PATCH] Show help if ``goto`` is issued without an address

---
 py65/monitor.py            | 3 +++
 py65/tests/test_monitor.py | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/py65/monitor.py b/py65/monitor.py
index eab4a8b..d28e1b2 100644
--- a/py65/monitor.py
+++ b/py65/monitor.py
@@ -429,6 +429,9 @@ class Monitor(cmd.Cmd):
         self._output("Change the PC to address and continue execution.")
 
     def do_goto(self, args):
+        if args == '':
+            return self.help_goto()
+
         self._mpu.pc = self._address_parser.number(args)
         brks = [0x00]  # BRK
         self._run(stopcodes=brks)
diff --git a/py65/tests/test_monitor.py b/py65/tests/test_monitor.py
index 37d3f6b..6c58cd1 100644
--- a/py65/tests/test_monitor.py
+++ b/py65/tests/test_monitor.py
@@ -417,6 +417,13 @@ class MonitorTests(unittest.TestCase):
         out = stdout.getvalue()
         self.assertTrue(out.startswith('goto'))
 
+    def test_goto_without_args_shows_command_help(self):
+        stdout = StringIO()
+        mon = Monitor(stdout=stdout)
+        mon.onecmd('goto')
+        out = stdout.getvalue()
+        self.assertTrue("goto <address>" in out)
+
     # help
 
     def test_help_without_args_shows_documented_commands(self):