From e74595fdd5a03544d53b8737b0046d243cd51466 Mon Sep 17 00:00:00 2001
From: Steven Franke <s.j.franke@icloud.com>
Date: Wed, 1 Jul 2020 16:42:22 -0500
Subject: [PATCH] Discard the all-zero codeword.

---
 lib/fst240_decode.f90 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/fst240_decode.f90 b/lib/fst240_decode.f90
index 2cb182b38..6d44f0cb7 100644
--- a/lib/fst240_decode.f90
+++ b/lib/fst240_decode.f90
@@ -515,6 +515,10 @@ contains
                   endif
 
                   if(nharderrors .ge.0) then
+                     if(count(cw.eq.1).eq.0) then
+                        nharderrors=-nharderrors
+                        cycle
+                     endif
                      if(iqorw.eq.1) then
                         write(c77,'(77i1)') mod(message101(1:77)+rvec,2)
                         call unpack77(c77,0,msg,unpk77_success)