From f19df05bdf273bcf51de45859cd81d8ba060ed66 Mon Sep 17 00:00:00 2001
From: Luke Campagnola <luke.campagnola@gmail.com>
Date: Fri, 18 Oct 2013 15:02:17 -0400
Subject: [PATCH] Allow AxisItem.setScale(None) to retain API backward
 compatibility.

---
 pyqtgraph/graphicsItems/AxisItem.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pyqtgraph/graphicsItems/AxisItem.py b/pyqtgraph/graphicsItems/AxisItem.py
index 531e3e9a..93efb45c 100644
--- a/pyqtgraph/graphicsItems/AxisItem.py
+++ b/pyqtgraph/graphicsItems/AxisItem.py
@@ -293,6 +293,11 @@ class AxisItem(GraphicsWidget):
         the view coordinate system were scaled. By default, the axis scaling is 
         1.0.
         """
+        # Deprecated usage, kept for backward compatibility
+        if scale is None:  
+            scale = 1.0
+            self.enableAutoSIPrefix(True)
+            
         if scale != self.scale:
             self.scale = scale
             self.setLabel()