Merge pull request #287 from pdxlocations:display-bug

Clear stale reply context in draw_text_field function and add corresponding test

contact/ui/contact_ui.py

@@ -1675,21 +1675,25 @@ def remove_notification(channel_number: int) -> None:
 
 def draw_text_field(win: curses.window, text: str, color: int) -> None:
     win.border()
+    height, width = win.getmaxyx()
 
     # Put a small hint in the border of the message entry field.
     # We key off the "Message:" prompt to avoid affecting other bordered fields.
     if isinstance(text, str) and text.startswith("Message:"):
         hint = " Ctrl+K Help "
-        h, w = win.getmaxyx()
-        x = max(2, w - len(hint) - 2)
+        x = max(2, width - len(hint) - 2)
         try:
             win.addstr(0, x, hint, get_color("commands"))
         except curses.error:
             pass
 
-    # Draw the actual field text
+    # Clear the row before redrawing.  Reply context can be longer than the
+    # next value (or empty after Ctrl+R cancels it), so simply overwriting the
+    # new text leaves trailing characters from the old context on screen.
     try:
-        win.addstr(1, 1, text, color)
+        if height > 2 and width > 2:
+            win.addstr(1, 1, " " * (width - 2), color)
+        win.addstr(1, 1, text[: max(0, width - 2)], color)
     except curses.error:
         pass
 

tests/test_contact_ui.py

@@ -152,6 +152,15 @@ class ContactUiTests(unittest.TestCase):
         self.assertEqual(ui_state.reply_context, "")
         self.assertFalse(ui_state.reply_id_unavailable)
 
+    def test_draw_text_field_clears_stale_reply_context(self) -> None:
+        win = mock.Mock()
+        win.getmaxyx.return_value = (3, 30)
+
+        contact_ui.draw_text_field(win, "Message: ", 1)
+
+        self.assertIn(mock.call(1, 1, " " * 28, 1), win.addstr.call_args_list)
+        self.assertIn(mock.call(1, 1, "Message: ", 1), win.addstr.call_args_list)
+
     def test_handle_ctrl_r_shows_context_when_message_id_is_unavailable(self) -> None:
         ui_state.current_window = 1
         ui_state.channel_list = ["Primary"]