From 65689c46cf401ab4fad40ca970f279ee506af401 Mon Sep 17 00:00:00 2001
From: Joe Taylor <joe@princeton.edu>
Date: Fri, 31 Aug 2018 13:55:44 -0400
Subject: [PATCH] Protect against a bounds error.

---
 lib/xcor4.f90 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/xcor4.f90 b/lib/xcor4.f90
index 9e1f5a529..9e4aff59b 100644
--- a/lib/xcor4.f90
+++ b/lib/xcor4.f90
@@ -37,7 +37,7 @@ subroutine xcor4(s2,ipk,nsteps,nsym,lag1,lag2,ich,mode4,ccf,ccf0,   &
 
   ccfmax=0.
   ccfmin=0.
-  nw=nch(ich)
+  nw=nch(min(max(ich,1),7))
 
   do j=1,nsteps
      n=2*mode4