Prevent crash if *line == NULL

src/spicelib/parser/inpgtok.c

@@ -31,6 +31,11 @@ INPgetTok(char **line, char **token, int gobble)
     char *point;
     int signstate;
 
+    if (!*line) {
+        *token = NULL;
+        return (E_PARMVAL);
+    }
+
     /* scan along throwing away garbage characters until end of line
        or a separation char is found */
     for (point = *line; *point != '\0'; point++) {