From cd0d73a1a21d1e4baa47f492818cb7a23e4b0c45 Mon Sep 17 00:00:00 2001
From: Robert Jordens <rj@m-labs.hk>
Date: Wed, 11 Oct 2017 22:25:14 +0200
Subject: [PATCH] scanwidget: protect against resize from zero

fix #839
---
 artiq/gui/scanwidget.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/artiq/gui/scanwidget.py b/artiq/gui/scanwidget.py
index 17ed5c8a3..20e161d97 100644
--- a/artiq/gui/scanwidget.py
+++ b/artiq/gui/scanwidget.py
@@ -223,7 +223,7 @@ class ScanWidget(QtWidgets.QWidget):
             self._zoom(self.zoomFactor**y, ev.x())
 
     def resizeEvent(self, ev):
-        if not ev.oldSize().isValid():
+        if not ev.oldSize().isValid() or not ev.oldSize().width():
             self.viewRange()
             return
         self.ticker.min_ticks = max(