From b24c613ce68769a05b710ba65783f61e22828248 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Wed, 17 May 2023 10:08:38 +0200
Subject: [PATCH] Safeguard against bad arguments (no crash upon NULL)

---
 src/spicelib/parser/inpptree.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/spicelib/parser/inpptree.c b/src/spicelib/parser/inpptree.c
index 4828c8fd4..398771048 100644
--- a/src/spicelib/parser/inpptree.c
+++ b/src/spicelib/parser/inpptree.c
@@ -1112,6 +1112,11 @@ INPparseNode *PT_mkfnode(const char *fname, INPparseNode * arg)
         return mkfirst(NULL, arg);
     }
 
+    if (!arg) {
+        fprintf(stderr, "Error: bad function arguments \n");
+        return mkfirst(NULL, arg);
+    }
+
     /* Make sure the case is ok. */
     (void)strncpy(buf, fname, 127);
     buf[127] = 0;