From 0b981408930ca34fd27f6c1dc3b094909b180544 Mon Sep 17 00:00:00 2001
From: Kenneth Lyons <ixjlyons@gmail.com>
Date: Sat, 20 Jun 2020 12:27:29 -0700
Subject: [PATCH] Check for container before setting dock orientation

---
 pyqtgraph/dockarea/Dock.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/pyqtgraph/dockarea/Dock.py b/pyqtgraph/dockarea/Dock.py
index 15c87652..083756dc 100644
--- a/pyqtgraph/dockarea/Dock.py
+++ b/pyqtgraph/dockarea/Dock.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 from ..Qt import QtCore, QtGui
 
 from .DockDrop import *
@@ -138,6 +139,12 @@ class Dock(QtGui.QWidget, DockDrop):
         By default ('auto'), the orientation is determined
         based on the aspect ratio of the Dock.
         """
+        # setOrientation may be called before the container is set in some cases
+        # (via resizeEvent), so there's no need to do anything here until called
+        # again by containerChanged
+        if self.container() is None:
+            return
+
         if o == 'auto' and self.autoOrient:
             if self.container().type() == 'tab':
                 o = 'horizontal'