plug memory leak in x11.c

try to obey the Xt toolkit protocol when closing widgets and application

src/frontend/display.c

@@ -419,7 +419,8 @@ int DevSwitch(char *devname)
 
     } else {
 
-        dispdev->Close();
+        if (dispdev)
+            dispdev->Close();
         dispdev = lastdev;
         lastdev = NULL;
 

src/frontend/misccoms.c

@@ -10,9 +10,11 @@ Author: 1985 Wayne A. Christopher, U. C. Berkeley CAD Group
 #include "ftehelp.h"
 #include "ngspice/hlpdefs.h"
 #include "misccoms.h"
+#include "postcoms.h"
 #include "circuits.h"
 #include "variable.h"
 #include "plotting/graf.h"
+#include "display.h"
 
 #ifdef HAVE_GNUREADLINE
 #include <readline/readline.h>
@@ -51,6 +53,12 @@ com_quit(wordlist *wl)
 
     /* start to clean up the mess */
 
+    {
+        wordlist *t = wl_cons(copy("all"), NULL);
+        com_destroy(t);
+        wl_free(t);
+    }
+
 #ifdef EXPERIMENTAL_CODE
     /* Destroy CKT when quit. Add by Gong Ding, gdiso@ustc.edu */
     if (!ft_nutmeg) {
@@ -61,6 +69,9 @@ com_quit(wordlist *wl)
     }
 #endif
 
+    DevSwitch(NULL);
+    DevSwitch(NULL);
+
     /* then go away */
     byemesg();
     exit(exitcode);

src/frontend/plotting/x11.c

@@ -507,7 +507,16 @@ X11_NewViewport(GRAPH *graph)
 int
 X11_Close(void)
 {
-    XCloseDisplay(display);
+    // don't, this has never been mapped, there is no window ...
+    // XtUnmapWidget(toplevel);
+    XtDestroyWidget(toplevel);
+
+    XtAppContext app = XtDisplayToApplicationContext(display);
+    XtDestroyApplicationContext(app);
+
+    // don't, XtDestroyApplicationContext(app) seems to have done that
+    // XCloseDisplay(display);
+
     return 0;
 }
 
@@ -909,7 +918,10 @@ RemoveWindow(GRAPH *graph)
         /* Iplots are done asynchronously */
         DEVDEP(graph).isopen = 0;
         /* MW. Not sure but DestroyGraph might free() to much - try Xt...() first */
+        XtUnmapWidget(DEVDEP(graph).shell);
         XtDestroyWidget(DEVDEP(graph).shell);
+        XFreeFont(display, DEVDEP(graph).font);
+        XFreeGC(display, DEVDEP(graph).gc);
     }
 
     if (graph == currentgraph)