Prevent memory leak.

Remove use controls.
Safeguard against NULL.

src/frontend/inp.c

@@ -1122,7 +1122,8 @@ inp_spsource(FILE *fp, bool comfile, char *filename, bool intfile)
             inputdir = dir_name;
 #endif
             if (cp_getvar("controlswait", CP_BOOL, NULL, 0)) {
-                exec_controls(wl_copy(wl));
+                if (wl)
+                    exec_controls(wl_copy(wl));
                 break;
             }
             else

src/sharedspice.c

@@ -485,6 +485,7 @@ _cthread_run(void *controls)
 #ifdef HAVE_LIBPTHREAD
     cont_condition = FALSE;
 #endif
+    wl_free(controls);
     return NULL;
 }
 
@@ -608,6 +609,7 @@ exec_controls(wordlist *newcontrols)
     wordlist *wl;
     for (wl = shcontrols; wl; wl = wl->wl_next)
         cp_evloop(wl->wl_word);
+    wl_free(shcontrols);
 #endif
 }