From 8a8ba9f44948ae96163f62feb573a833dffacdf5 Mon Sep 17 00:00:00 2001
From: Karthik Nadig <kanadig@microsoft.com>
Date: Fri, 4 May 2018 13:55:57 -0700
Subject: [PATCH] Handle KeyError while getting or setting variables (#413)

---
 ptvsd/wrapper.py                 | 12 ++++++++--
 tests/highlevel/test_messages.py | 40 ++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/ptvsd/wrapper.py b/ptvsd/wrapper.py
index 651ed71e..fe41997f 100644
--- a/ptvsd/wrapper.py
+++ b/ptvsd/wrapper.py
@@ -1292,7 +1292,11 @@ class VSCodeMessageProcessor(ipcjson.SocketIO, ipcjson.IpcChannel):
         vsc_var = int(args['variablesReference'])
         fmt = args.get('format', {})
 
-        pyd_var = self.var_map.to_pydevd(vsc_var)
+        try:
+            pyd_var = self.var_map.to_pydevd(vsc_var)
+        except KeyError:
+            self.send_error_response(request)
+            return
 
         if len(pyd_var) == 3:
             cmd = pydevd_comm.CMD_GET_FRAME
@@ -1383,7 +1387,11 @@ class VSCodeMessageProcessor(ipcjson.SocketIO, ipcjson.IpcChannel):
         """Handles DAP SetVariableRequest."""
 
         vsc_var = int(args['variablesReference'])
-        pyd_var = self.var_map.to_pydevd(vsc_var)
+        try:
+            pyd_var = self.var_map.to_pydevd(vsc_var)
+        except KeyError:
+            self.send_error_response(request)
+            return
 
         var_name = args['name']
         var_value = args['value']
diff --git a/tests/highlevel/test_messages.py b/tests/highlevel/test_messages.py
index 92cc215d..50e56f35 100644
--- a/tests/highlevel/test_messages.py
+++ b/tests/highlevel/test_messages.py
@@ -449,6 +449,25 @@ class VariablesTests(NormalRequestTest, unittest.TestCase):
             self.expected_pydevd_request('{}\t2\tFRAME'.format(thread.id)),
         ])
 
+    def test_invalid_var_ref(self):
+        with self.launched():
+            with self.hidden():
+                _, thread = self.pause('t', *[
+                    # (pfid, func, file, line)
+                    (2, 'spam', 'abc.py', 10),  # VSC frame ID 1
+                    (5, 'eggs', 'xyz.py', 2),  # VSC frame ID 2
+                ])
+            self.send_request(
+                # should NOT match variable or frame ID
+                variablesReference=12345,
+            )
+            received = self.vsc.received
+
+        self.assert_vsc_received(received, [
+            self.expected_failure(''),
+            # no events
+        ])
+
     def test_container(self):
         self.PYDEVD_CMD = CMD_GET_FRAME
         with self.launched():
@@ -570,6 +589,27 @@ class SetVariableTests(NormalRequestTest, unittest.TestCase):
                 '{}\t2\tLOCAL\tspam\t1'.format(thread.id)),
         ])
 
+    def test_invalid_var_ref(self):
+        with self.launched():
+            with self.hidden():
+                _, thread = self.pause('t', *[
+                    # (pfid, func, file, line)
+                    (2, 'spam', 'abc.py', 10),  # VSC frame ID 1
+                    (5, 'eggs', 'xyz.py', 2),  # VSC frame ID 2
+                ])
+            self.send_request(
+                # should NOT match any variable or frame ID
+                variablesReference=12345,
+                name='spam',
+                value='eggs',
+            )
+            received = self.vsc.received
+
+        self.assert_vsc_received(received, [
+            self.expected_failure(''),
+            # no events
+        ])
+
     def test_container(self):
         with self.launched():
             with self.hidden():