# HG changeset patch
# User Rik <rik@octave.org>
# Date 1506112588 25200
# Node ID 88a593fa1388fd5cc05ad313552350925fc3330a
# Parent  2a9eec536cfd515889b9067128bec8b2a396d84d
Stop out-of-bounds memory access during convolution (bug #52067).

* oct-convn.cc (convolve): Check size of return matrix and short-circuit return
from function if it is empty (as can happen when shape == "valid").

diff -r 2a9eec536cfd -r 88a593fa1388 liboctave/numeric/oct-convn.cc
--- a/liboctave/numeric/oct-convn.cc	Fri Sep 22 12:46:53 2017 -0700
+++ b/liboctave/numeric/oct-convn.cc	Fri Sep 22 13:36:28 2017 -0700
@@ -152,6 +152,11 @@
 
   MArray<T> c (cdims, T ());
 
+  // "valid" shape can sometimes result in empty matrices which must avoid
+  // calling Fortran code which does not expect this (bug #52067)
+  if (c.isempty ())
+    return c;
+
   convolve_nd<T, R> (a.fortran_vec (), adims, adims.cumulative (),
                      b.fortran_vec (), bdims, bdims.cumulative (),
                      c.fortran_vec (), cdims.cumulative (),