From b2199e299a6ca6d866aa6f3d0888499136ead9d6 Mon Sep 17 00:00:00 2001
From: Scott Talbert <swt@techie.net>
Date: Tue, 11 Jan 2022 19:55:51 -0500
Subject: [PATCH] plotcanvas: avoid trying to adjust scrollbars if nothing
 drawn

For example, if Clear() is called on a plotcanvas, _adjustScrollbars()
will not work, so avoid trying to do it if nothing is drawn currently.
---
 wx/lib/plot/plotcanvas.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/wx/lib/plot/plotcanvas.py b/wx/lib/plot/plotcanvas.py
index 763e2c0a..ec799ffe 100644
--- a/wx/lib/plot/plotcanvas.py
+++ b/wx/lib/plot/plotcanvas.py
@@ -707,7 +707,8 @@ class PlotCanvas(wx.Panel):
 
         def _do_update():
             self.Layout()
-            self._adjustScrollbars()
+            if self.last_draw is not None:
+                self._adjustScrollbars()
         wx.CallAfter(_do_update)
 
     def SetUseScientificNotation(self, useScientificNotation):