Fix Coverity Uninitialized Scalar Warnings

Coverity notes that SDL_UserEvent.windowID is never initialized. SDL documents that memset() should be used to initialize the structure. Subclassing the struct to add various constructors for clarity and future-proofing.

This closes

    CID 1380246
    CID 1380234
    CID 1380159
    CID 1380152
    CID 1356356

Earlier commit for these warnings only fixed the timestamp.

src/events.cpp

@@ -18,6 +18,7 @@
 #include "log.hpp"
 #include "quit_confirmation.hpp"
 #include "video.hpp"
+#include "sdl/userevent.hpp"
 
 #if defined _WIN32
 #include "desktop/windows_tray_notification.hpp"
@@ -548,12 +549,7 @@ void pump()
 						&& std::abs(event.button.x - last_click_x) < DoubleClickMaxMove
 						&& std::abs(event.button.y - last_click_y) < DoubleClickMaxMove
 				) {
-					SDL_UserEvent user_event;
-					user_event.type = DOUBLE_CLICK_EVENT;
-					user_event.code = 0;
-					user_event.data1 = reinterpret_cast<void*>(event.button.x);
-					user_event.data2 = reinterpret_cast<void*>(event.button.y);
-					user_event.timestamp = std::time(nullptr);
+					sdl::UserEvent user_event(DOUBLE_CLICK_EVENT, event.button.x, event.button.y);
 					::SDL_PushEvent(reinterpret_cast<SDL_Event*>(&user_event));
 				}
 
@@ -755,13 +751,7 @@ void call_in_main_thread(const std::function<void(void)>& f)
 	invoked_function_data fdata{false, f};
 
 	SDL_Event sdl_event;
-	SDL_UserEvent sdl_userevent;
-
-	sdl_userevent.type = INVOKE_FUNCTION_EVENT;
-	sdl_userevent.code = 0;
-	sdl_userevent.data1 = &fdata;
-	sdl_userevent.data2 = nullptr;
-	sdl_userevent.timestamp = std::time(nullptr);
+	sdl::UserEvent sdl_userevent(INVOKE_FUNCTION_EVENT, &fdata);
 
 	sdl_event.type = INVOKE_FUNCTION_EVENT;
 	sdl_event.user = sdl_userevent;

src/gui/core/event/distributor.cpp

@@ -23,6 +23,7 @@
 #include "gui/widgets/widget.hpp"
 #include "gui/widgets/window.hpp"
 #include "gui/widgets/text_box_base.hpp"
+#include "sdl/userevent.hpp"
 
 #include "utils/functional.hpp"
 
@@ -60,13 +61,7 @@ static Uint32 popup_callback(Uint32 /*interval*/, void* /*param*/)
 	DBG_GUI_E << "Pushing popup removal event in queue.\n";
 
 	SDL_Event event;
-	SDL_UserEvent data;
-
-	data.type = HOVER_REMOVE_POPUP_EVENT;
-	data.code = 0;
-	data.data1 = 0;
-	data.data2 = 0;
-	data.timestamp = std::time(nullptr);
+	sdl::UserEvent data(HOVER_REMOVE_POPUP_EVENT);
 
 	event.type = HOVER_REMOVE_POPUP_EVENT;
 	event.user = data;

src/gui/core/event/handler.cpp

@@ -25,6 +25,7 @@
 #include "hotkey/hotkey_item.hpp"
 #include "video.hpp"
 #include "serialization/unicode_cast.hpp"
+#include "sdl/userevent.hpp"
 
 #include <cassert>
 
@@ -79,13 +80,7 @@ static Uint32 timer_sdl_draw_event(Uint32, void*)
 	// DBG_GUI_E << "Pushing draw event in queue.\n";
 
 	SDL_Event event;
-	SDL_UserEvent data;
-
-	data.type = DRAW_EVENT;
-	data.code = 0;
-	data.data1 = nullptr;
-	data.data2 = nullptr;
-	data.timestampt = std::time(nullptr);
+	sdl::UserEvent data(DRAW_EVENT);
 
 	event.type = DRAW_EVENT;
 	event.user = data;

src/gui/widgets/window.cpp

@@ -61,6 +61,7 @@
 #include "formula/variant.hpp"
 #include "video.hpp"
 #include "wml_exception.hpp"
+#include "sdl/userevent.hpp"
 
 #include "utils/functional.hpp"
 
@@ -136,13 +137,7 @@ static Uint32 draw_timer(Uint32, void*)
 	//	DBG_GUI_E << "Pushing draw event in queue.\n";
 
 	SDL_Event event;
-	SDL_UserEvent data;
-
-	data.type = DRAW_EVENT;
-	data.code = 0;
-	data.data1 = nullptr;
-	data.data2 = nullptr;
-	data.timestamp = std::time(nullptr);
+	sdl::UserEvent data(DRAW_EVENT);
 
 	event.type = DRAW_EVENT;
 	event.user = data;
@@ -189,13 +184,7 @@ static bool helptip()
 	DBG_GUI_E << "Pushing SHOW_HELPTIP_EVENT event in queue.\n";
 
 	SDL_Event event;
-	SDL_UserEvent data;
-
-	data.type = SHOW_HELPTIP_EVENT;
-	data.code = 0;
-	data.data1 = nullptr;
-	data.data2 = nullptr;
-	data.timestamp = std::time(nullptr);
+	sdl::UserEvent data(SHOW_HELPTIP_EVENT);
 
 	event.type = SHOW_HELPTIP_EVENT;
 	event.user = data;
@@ -600,13 +589,7 @@ int window::show(const bool restore, const unsigned auto_close_timeout)
 		draw();
 
 		SDL_Event event;
-		SDL_UserEvent data;
-
-		data.type = CLOSE_WINDOW_EVENT;
-		data.code = manager::instance().get_id(*this);
-		data.data1 = nullptr;
-		data.data2 = nullptr;
-		data.timestamp = std::time(nullptr);
+		sdl::UserEvent data(CLOSE_WINDOW_EVENT, manager::instance().get_id(*this));
 
 		event.type = CLOSE_WINDOW_EVENT;
 		event.user = data;

src/sdl/userevent.hpp

@@ -0,0 +1,43 @@
+/*
+   Copyright (C) 2017 the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#pragma once
+
+#include <SDL_events.h>
+
+namespace sdl
+{
+    class UserEvent : public SDL_UserEvent
+    {
+        public:
+            UserEvent() : SDL_UserEvent() {
+            }
+
+            UserEvent(int type) : UserEvent() {
+                this->type = type;
+            }
+
+            UserEvent(int type, int code) : UserEvent(type) {
+                this->code = code;
+            }
+
+            UserEvent(int type, int data1, int data2) : UserEvent(type) {
+                this->data1 = reinterpret_cast<void*>(data1);
+                this->data2 = reinterpret_cast<void*>(data2);
+            }
+
+            UserEvent(int type, void* data1) : UserEvent(type) {
+                this->data1 = data1;
+            }
+    };
+}

src/video.cpp

@@ -20,6 +20,7 @@
 #include "log.hpp"
 #include "preferences/general.hpp"
 #include "sdl/window.hpp"
+#include "sdl/userevent.hpp"
 
 #include <cassert>
 #include <vector>
@@ -66,13 +67,7 @@ void trigger_full_redraw() {
 	}
 
 	SDL_Event drawEvent;
-	SDL_UserEvent data;
-
-	data.type = DRAW_ALL_EVENT;
-	data.code = 0;
-	data.data1 = nullptr;
-	data.data2 = nullptr;
-	data.timestamp = std::time(nullptr);
+	sdl::UserEvent data(DRAW_ALL_EVENT);
 
 	drawEvent.type = DRAW_ALL_EVENT;
 	drawEvent.user = data;
@@ -153,13 +148,7 @@ void CVideo::video_event_handler::handle_window_event(const SDL_Event &event)
 				//if(display::get_singleton())
 					//display::get_singleton()->redraw_everything();
 				SDL_Event drawEvent;
-				SDL_UserEvent data;
-
-				data.type = DRAW_ALL_EVENT;
-				data.code = 0;
-				data.data1 = nullptr;
-				data.data2 = nullptr;
-				data.timestamp = std::time(nullptr);
+				sdl::UserEvent data(DRAW_ALL_EVENT);
 
 				drawEvent.type = DRAW_ALL_EVENT;
 				drawEvent.user = data;