Guard XSPICE plot switching against circuit being removed already

src/frontend/vectors.c

@@ -1111,6 +1111,11 @@ void plot_setcur(const char *name)
     else if (cieq(name, "previous")) {
         if (plot_cur->pl_next) {
             plot_cur = plot_cur->pl_next;
+#ifdef XSPICE
+            if (ft_curckt) {
+                EVTswitch_plot(ft_curckt->ci_ckt, plot_cur->pl_typename);
+            }
+#endif
         }
         else {
             fprintf(cp_err,
@@ -1131,7 +1136,11 @@ void plot_setcur(const char *name)
         }
         if (prev_pl) { /* found */
             plot_cur = prev_pl;
-            EVTswitch_plot(ft_curckt->ci_ckt, plot_cur->pl_typename);
+#ifdef XSPICE
+            if (ft_curckt) {
+                EVTswitch_plot(ft_curckt->ci_ckt, plot_cur->pl_typename);
+            }
+#endif
         }
         else { /* no next plot */
             fprintf(cp_err,
@@ -1156,7 +1165,14 @@ void plot_setcur(const char *name)
      plot_cur->pl_ccom = cp_kwswitch(CT_VECTOR, pl->pl_ccom);
      }
     */
-    EVTswitch_plot(ft_curckt->ci_ckt, name);
+#ifdef XSPICE
+    /* XSPICE event data are linked to the current circuit. It must not be removed
+       when manipulating the data by any command.
+    */
+    if (ft_curckt) {
+        EVTswitch_plot(ft_curckt->ci_ckt, name);
+    }
+#endif
     plot_cur = pl;
 } /* end of function plot_setcur */
 

src/xspice/evt/evtsetup.c

@@ -617,7 +617,9 @@ int EVTsetup_plot(CKTcircuit* ckt, char *plotname) {
 }
 
 /* If command 'setplot' is called, we switch to the corresponding event data.
-   Their pointers have been stored in the jobs structure.*/
+   Their pointers have been stored in the jobs structure. The circuit must
+   be still available!
+*/
 int EVTswitch_plot(CKTcircuit* ckt, const char* plottypename) {
     int i;
     bool found = FALSE;