From 60cc4361b69d5e520f797527510e89d71eaa4fa6 Mon Sep 17 00:00:00 2001
From: Eric Firing <efiring@hawaii.edu>
Date: Sat, 31 May 2014 21:16:08 -1000
Subject: [PATCH] Image: handle images with zero columns or rows.

Two methods in the _image extension module now raise an
exception if the number of rows or columns is zero;
previously they could segfault.  A particular
circumstance that can cause this (setting xlim completely
outside the image extent) is handled directly in the
image module without raising an exception.

Closes #3091.
---
 lib/matplotlib/image.py | 2 ++
 src/_image.cpp          | 6 +++---
 src/_image.h            | 6 ++++++
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
index f2c471a71f89..0f6cd2750ee8 100644
--- a/lib/matplotlib/image.py
+++ b/lib/matplotlib/image.py
@@ -327,6 +327,8 @@ def _draw_unsampled_image(self, renderer, gc):
         im.reset_matrix()
         numrows, numcols = im.get_size()
 
+        if numrows <= 0 or numcols <= 0:
+            return
         im.resize(numcols, numrows)  # just to create im.bufOut that
                                      # is required by backends. There
                                      # may be better solution -JJL
diff --git a/src/_image.cpp b/src/_image.cpp
index b85cdf2af9f6..b1c59e9674ba 100644
--- a/src/_image.cpp
+++ b/src/_image.cpp
@@ -374,10 +374,10 @@ Image::resize(const Py::Tuple& args, const Py::Dict& kwargs)
     int numcols = Py::Int(args[0]);
     int numrows = Py::Int(args[1]);
 
-    if (numcols < 0 || numrows < 0)
+    if (numcols <= 0 || numrows <= 0)
     {
-	throw Py::RuntimeError(
-	    "Width and height must have non-negative values");
+        throw Py::RuntimeError(
+        "Width and height must have positive values");
     }
 
     colsOut = numcols;
diff --git a/src/_image.h b/src/_image.h
index 425bc2462ff3..aa0de94174cd 100644
--- a/src/_image.h
+++ b/src/_image.h
@@ -45,6 +45,12 @@ class Image : public Py::PythonExtension<Image>
     inline Py::Object flipud_out(const Py::Tuple& args)
     {
         args.verify_length(0);
+        if (colsOut <= 0 || rowsOut <= 0)
+        {
+            throw Py::RuntimeError(
+            "Width and height must have positive values");
+        }
+
         int stride = rbufOut->stride();
         //std::cout << "flip before: " << rbufOut->stride() << std::endl;
         rbufOut->attach(bufferOut, colsOut, rowsOut, -stride);