clear all variables upon 'quit'

src/frontend/com_unset.c

@@ -10,6 +10,7 @@
 #include "com_unset.h"
 #include "variable.h"
 
+/* clear variables (by name or all) */
 void
 com_unset(wordlist *wl)
 {
@@ -29,3 +30,12 @@ com_unset(wordlist *wl)
         wl = wl->wl_next;
     }
 }
+
+/* clear all variables (called from com_quit) */
+void unset_all(void){
+    struct variable *var, *nv;
+    for (var = variables; var; var = nv) {
+        nv = var->va_next;
+        cp_remvar(var->va_name);
+    }
+}

src/frontend/com_unset.h

@@ -8,5 +8,6 @@
 #include "ngspice/wordlist.h"
 
 void com_unset(wordlist *wl);
+void unset_all(void);
 
 #endif

src/frontend/misccoms.c

@@ -108,6 +108,7 @@ com_quit(wordlist *wl)
 #ifdef SHARED_MODULE
     destroy_const_plot();
     spice_destroy_devices();
+    unset_all();
     cp_resetcontrol(FALSE);
     /* add 1000 to notify that we exit from 'quit' */
     controlled_exit(1000 + exitcode);