GTK: Ensure core windows are fully initialised.

frontends/gtk/cookies.c

@@ -246,7 +246,7 @@ static nserror nsgtk_cookies_init(void)
 		return NSERROR_OK;
 	}
 
-	ncwin = malloc(sizeof(struct nsgtk_cookie_window));
+	ncwin = calloc(1, sizeof(*ncwin));
 	if (ncwin == NULL) {
 		return NSERROR_NOMEM;
 	}

frontends/gtk/global_history.c

@@ -299,7 +299,7 @@ static nserror nsgtk_global_history_init(void)
 		return NSERROR_OK;
 	}
 
-	ncwin = malloc(sizeof(struct nsgtk_global_history_window));
+	ncwin = calloc(1, sizeof(*ncwin));
 	if (ncwin == NULL) {
 		return NSERROR_NOMEM;
 	}

frontends/gtk/hotlist.c

@@ -319,7 +319,7 @@ static nserror nsgtk_hotlist_init(void)
 		return NSERROR_OK;
 	}
 
-	ncwin = malloc(sizeof(struct nsgtk_hotlist_window));
+	ncwin = calloc(1, sizeof(*ncwin));
 	if (ncwin == NULL) {
 		return NSERROR_NOMEM;
 	}

frontends/gtk/local_history.c

@@ -141,7 +141,7 @@ nsgtk_local_history_init(struct browser_window *bw,
 		return res;
 	}
 
-	ncwin = malloc(sizeof(struct nsgtk_local_history_window));
+	ncwin = calloc(1, sizeof(*ncwin));
 	if (ncwin == NULL) {
 		return NSERROR_NOMEM;
 	}