From 71149768c6cbbcb8f6bb48bca24db61de45ef8d0 Mon Sep 17 00:00:00 2001
From: Steve Plimpton <sjplimp@sandia.gov>
Date: Thu, 7 May 2020 10:42:40 -0600
Subject: [PATCH] fix atom_vec_hybrid bug

---
 src/atom_vec_hybrid.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/atom_vec_hybrid.cpp b/src/atom_vec_hybrid.cpp
index 7f47f64d91..51f484711c 100644
--- a/src/atom_vec_hybrid.cpp
+++ b/src/atom_vec_hybrid.cpp
@@ -214,7 +214,7 @@ void AtomVecHybrid::process_args(int narg, char **arg)
   for (int idup = 0; idup < ndupfield; idup++) {
     char *dup = (char *) dupfield[idup];
     ptr = strstr(concat_grow,dup);
-    if (strstr(ptr+1,dup)) {
+    if (ptr && strstr(ptr+1,dup)) {
       char str[128];
       sprintf(str,"Peratom %s is in multiple sub-styles - "
               "must be used consistently",dup);
@@ -565,7 +565,7 @@ void AtomVecHybrid::build_styles()
 #undef ATOM_CLASS
 
   allstyles = new char*[nallstyles];
-
+  
   int n;
   nallstyles = 0;
 #define ATOM_CLASS