From 62d3e3a51d80792bdf50e1186dc835fc7707d040 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Sat, 28 Jun 2025 16:07:42 +0200
Subject: [PATCH] Prevent from endless loop if step evaluates to 0.

---
 src/spicelib/parser/inp2dot.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/spicelib/parser/inp2dot.c b/src/spicelib/parser/inp2dot.c
index 5285297b5..7c871cc66 100644
--- a/src/spicelib/parser/inp2dot.c
+++ b/src/spicelib/parser/inp2dot.c
@@ -313,6 +313,8 @@ dot_dc(char *line, CKTcircuit *ckt, INPtables *tab, struct card *current,
     if (*line == '\0')
         return 1;
     parm = INPgetValue(ckt, &line, IF_REAL, tab);	/* vinc1 */
+        if (parm->rValue == 0)
+            return 1;
     GCA(INPapName, (ckt, which, foo, "step1", parm));
     if (*line) {
         INPgetTok(&line, &name, 1);
@@ -330,6 +332,8 @@ dot_dc(char *line, CKTcircuit *ckt, INPtables *tab, struct card *current,
             return 1;
         GCA(INPapName, (ckt, which, foo, "stop2", parm));
         parm = INPgetValue(ckt, &line, IF_REAL, tab); /* vinc2 */
+        if (parm->rValue == 0)
+            return 1;
         GCA(INPapName, (ckt, which, foo, "step2", parm));
     }
     return 0;