gnu: openbabel: Fix crash when opening NWChem output files.

* gnu/packages/patches/openbabel-fix-crash-on-nwchem-output.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/chemistry.scm (openbabel)[source]: Use it.

gnu/local.mk

@@ -979,6 +979,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/ocaml-graph-honor-source-date-epoch.patch	\
   %D%/packages/patches/omake-fix-non-determinism.patch	\
   %D%/packages/patches/ola-readdir-r.patch			\
+  %D%/packages/patches/openbabel-fix-crash-on-nwchem-output.patch	\
   %D%/packages/patches/opencascade-oce-glibc-2.26.patch		\
   %D%/packages/patches/openblas-fix-tests-i686.patch		\
   %D%/packages/patches/openexr-missing-samples.patch		\

gnu/packages/chemistry.scm

@@ -213,7 +213,9 @@ NumPy < 1.9.")
                                   version "/" name "-" version ".tar.gz"))
               (sha256
                (base32
-                "1z3d6xm70dpfikhwdnbzc66j2l49vq105ch041wivrfz5ic3ch90"))))
+                "1z3d6xm70dpfikhwdnbzc66j2l49vq105ch041wivrfz5ic3ch90"))
+              (patches
+               (search-patches "openbabel-fix-crash-on-nwchem-output.patch"))))
     (build-system cmake-build-system)
     (arguments
      `(#:configure-flags

gnu/packages/patches/openbabel-fix-crash-on-nwchem-output.patch

@@ -0,0 +1,34 @@
+From 52cea818bf68f8a2d3c48d55d00c2f8b7da25e4c Mon Sep 17 00:00:00 2001
+From: Daniel Hogan <daniel.hogan@usask.ca>
+Date: Tue, 28 Mar 2017 22:21:18 -0600
+Subject: [PATCH] Remove delete statement.
+
+When from_scratch is true, coordinates is not allocated. A separate if
+statement was added to handle the case when from_scratch is true that
+does not try to free coordinates.
+---
+ src/formats/nwchemformat.cpp | 9 ++++++---
+ 1 file changed, 6 insertions(+), 3 deletions(-)
+
+diff --git a/src/formats/nwchemformat.cpp b/src/formats/nwchemformat.cpp
+index 6f625ad5b..79298555f 100644
+--- a/src/formats/nwchemformat.cpp
++++ b/src/formats/nwchemformat.cpp
+@@ -232,11 +232,14 @@ static const char* OPTIMIZATION_END_PATTERN = "  Optimization converged";
+           break;
+         tokenize(vs,buffer);
+     }
+-    if ((from_scratch)||(i != natoms))
+-      {
++    if (from_scratch) 
++    {
++        return;
++    }
++    if (i != natoms) {
+         delete[] coordinates;
+         return;
+-      }
++    }
+     molecule->AddConformer(coordinates);
+   }
+