test for 2gb numpy image segfault

Tests/large_memory_numpy_test.py

@@ -0,0 +1,37 @@
+from tester import *
+
+# This test is not run automatically.
+#
+# It requires > 2gb memory for the >2 gigapixel image generated in the
+# second test.  Running this automatically would amount to a denial of
+# service on our testing infrastructure.  I expect this test to fail
+# on any 32 bit machine, as well as any smallish things (like
+# raspberrypis).
+
+from PIL import Image
+try:
+    import numpy as np
+except:
+    skip()
+    
+ydim = 32769
+xdim = 48000
+f = tempfile('temp.png')
+
+def _write_png(xdim,ydim):
+    dtype = np.uint8
+    a = np.zeros((xdim, ydim), dtype=dtype)
+    im = Image.fromarray(a, 'L')
+    im.save(f)
+    success()
+
+def test_large():
+    """ succeeded prepatch"""
+    _write_png(xdim,ydim)
+def test_2gpx():
+    """failed prepatch"""
+    _write_png(xdim,xdim)
+
+
+
+