From a4be66b9b040ece87727a2999565f20722ba1370 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Tue, 22 Jun 2021 00:19:43 +0200
Subject: [PATCH] Prevent crash if there is bad syntax in h, g, e, or f line

---
 src/frontend/inpcom.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index bef126e7c..498ff83b9 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -9671,8 +9671,11 @@ static int inp_poly_2g6_compat(struct card* deck) {
             curr_line = nexttok_noparens(curr_line);
             curr_line = nexttok_noparens(curr_line);
             curr_line = nexttok_noparens(curr_line);
-            if (!curr_line)
+            if (!curr_line) {
+                fprintf(stderr, "Error: bad syntax of line\n   %s\n", thisline);
+                fprintf(stderr, "No circuit loaded!\n");
                 return 1;
+            }
             /* exclude all of the following fourth tokens */
             if (ciprefix("poly", curr_line))
                 continue;