From f929f40c51078ce9d69f5d2a9788786fee190c82 Mon Sep 17 00:00:00 2001
From: Eric Dill <thedizzle@gmail.com>
Date: Sat, 11 Jul 2015 17:43:07 -0500
Subject: [PATCH 1/3] BUG: Divide by zero error in ImageItem autoDownsample

---
 pyqtgraph/graphicsItems/ImageItem.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pyqtgraph/graphicsItems/ImageItem.py b/pyqtgraph/graphicsItems/ImageItem.py
index 5b041433..4447d4b3 100644
--- a/pyqtgraph/graphicsItems/ImageItem.py
+++ b/pyqtgraph/graphicsItems/ImageItem.py
@@ -293,6 +293,9 @@ class ImageItem(GraphicsObject):
             h = Point(y-o).length()
             xds = max(1, int(1/w))
             yds = max(1, int(1/h))
+            # xds = int(1/max(1,w))
+            # yds = int(1/max(1,h))
+            # 1/0
             image = fn.downsample(self.image, xds, axis=0)
             image = fn.downsample(image, yds, axis=1)
         else:

From a52d8f7222997c55377e42f2988eb32f0bfdfdff Mon Sep 17 00:00:00 2001
From: Eric Dill <thedizzle@gmail.com>
Date: Sat, 11 Jul 2015 17:43:30 -0500
Subject: [PATCH 2/3] TST: Barn door testing on the divide-by-zero error

---
 .../graphicsItems/tests/test_ImageItem.py     | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 pyqtgraph/graphicsItems/tests/test_ImageItem.py

diff --git a/pyqtgraph/graphicsItems/tests/test_ImageItem.py b/pyqtgraph/graphicsItems/tests/test_ImageItem.py
new file mode 100644
index 00000000..ce232296
--- /dev/null
+++ b/pyqtgraph/graphicsItems/tests/test_ImageItem.py
@@ -0,0 +1,65 @@
+import gc
+import weakref
+# try:
+#     import faulthandler
+#     faulthandler.enable()
+# except ImportError:
+#     pass
+
+from pyqtgraph.Qt import QtCore, QtGui, QtTest
+import numpy as np
+import pyqtgraph as pg
+app = pg.mkQApp()
+
+
+def test_dividebyzero():
+    import pyqtgraph as pg
+    im = pg.image(pg.np.random.normal(size=(100,100)))
+    im.imageItem.setAutoDownsample(True)
+    im.view.setRange(xRange=[-5+25, 5e+25],yRange=[-5e+25, 5e+25])
+    app.processEvents()
+    QtTest.QTest.qWait(1000)
+    # must manually call im.imageItem.render here or the exception
+    # will only exist on the Qt event loop
+    im.imageItem.render()
+
+
+if __name__ == "__main__":
+    test_dividebyzero()
+
+
+# def test_getViewWidget():
+#     view = pg.PlotWidget()
+#     vref = weakref.ref(view)
+#     item = pg.InfiniteLine()
+#     view.addItem(item)
+#     assert item.getViewWidget() is view
+#     del view
+#     gc.collect()
+#     assert vref() is None
+#     assert item.getViewWidget() is None
+#
+# def test_getViewWidget_deleted():
+#     view = pg.PlotWidget()
+#     item = pg.InfiniteLine()
+#     view.addItem(item)
+#     assert item.getViewWidget() is view
+#
+#     # Arrange to have Qt automatically delete the view widget
+#     obj = pg.QtGui.QWidget()
+#     view.setParent(obj)
+#     del obj
+#     gc.collect()
+#
+#     assert not pg.Qt.isQObjectAlive(view)
+#     assert item.getViewWidget() is None
+
+
+#if __name__ == '__main__':
+    #view = pg.PlotItem()
+    #vref = weakref.ref(view)
+    #item = pg.InfiniteLine()
+    #view.addItem(item)
+    #del view
+    #gc.collect()
+    

From 3bdb29e5212992523d155ea090837261c59175b6 Mon Sep 17 00:00:00 2001
From: Eric Dill <thedizzle@gmail.com>
Date: Sat, 11 Jul 2015 17:44:50 -0500
Subject: [PATCH 3/3] MNT: Remove commented code

---
 pyqtgraph/graphicsItems/ImageItem.py          |  7 +---
 .../graphicsItems/tests/test_ImageItem.py     | 41 -------------------
 2 files changed, 2 insertions(+), 46 deletions(-)

diff --git a/pyqtgraph/graphicsItems/ImageItem.py b/pyqtgraph/graphicsItems/ImageItem.py
index 4447d4b3..744e1937 100644
--- a/pyqtgraph/graphicsItems/ImageItem.py
+++ b/pyqtgraph/graphicsItems/ImageItem.py
@@ -291,11 +291,8 @@ class ImageItem(GraphicsObject):
             y = self.mapToDevice(QtCore.QPointF(0,1))
             w = Point(x-o).length()
             h = Point(y-o).length()
-            xds = max(1, int(1/w))
-            yds = max(1, int(1/h))
-            # xds = int(1/max(1,w))
-            # yds = int(1/max(1,h))
-            # 1/0
+            xds = int(1/max(1, w))
+            yds = int(1/max(1, h))
             image = fn.downsample(self.image, xds, axis=0)
             image = fn.downsample(image, yds, axis=1)
         else:
diff --git a/pyqtgraph/graphicsItems/tests/test_ImageItem.py b/pyqtgraph/graphicsItems/tests/test_ImageItem.py
index ce232296..c2ba58d9 100644
--- a/pyqtgraph/graphicsItems/tests/test_ImageItem.py
+++ b/pyqtgraph/graphicsItems/tests/test_ImageItem.py
@@ -22,44 +22,3 @@ def test_dividebyzero():
     # must manually call im.imageItem.render here or the exception
     # will only exist on the Qt event loop
     im.imageItem.render()
-
-
-if __name__ == "__main__":
-    test_dividebyzero()
-
-
-# def test_getViewWidget():
-#     view = pg.PlotWidget()
-#     vref = weakref.ref(view)
-#     item = pg.InfiniteLine()
-#     view.addItem(item)
-#     assert item.getViewWidget() is view
-#     del view
-#     gc.collect()
-#     assert vref() is None
-#     assert item.getViewWidget() is None
-#
-# def test_getViewWidget_deleted():
-#     view = pg.PlotWidget()
-#     item = pg.InfiniteLine()
-#     view.addItem(item)
-#     assert item.getViewWidget() is view
-#
-#     # Arrange to have Qt automatically delete the view widget
-#     obj = pg.QtGui.QWidget()
-#     view.setParent(obj)
-#     del obj
-#     gc.collect()
-#
-#     assert not pg.Qt.isQObjectAlive(view)
-#     assert item.getViewWidget() is None
-
-
-#if __name__ == '__main__':
-    #view = pg.PlotItem()
-    #vref = weakref.ref(view)
-    #item = pg.InfiniteLine()
-    #view.addItem(item)
-    #del view
-    #gc.collect()
-