Fixed non-autorail building with confirmation dialog, UI is still slightly broken

src/build_confirmation_gui.cpp

@@ -33,10 +33,16 @@
 struct BuildConfirmationWindow : Window {
 
 	// TODO: show estimated price
-	static bool shown; // Just to speed up window hiding, HideBuildConfirmationWindow() is called very often
+	static bool shown;   ///< Just to speed up window hiding, HideBuildConfirmationWindow() is called very often.
+	Point selstart;      ///< The selection start on the viewport.
+	Point selend;        ///< The selection end on the viewport.
 
 	BuildConfirmationWindow(WindowDesc *desc) : Window(desc)
 	{
+		// Save tile selection points, they will be reset by subsequent code, and we must keep them
+		selstart = _thd.selstart;
+		selend = _thd.selend;
+
 		this->InitNested(0);
 
 		Point pt;
@@ -67,6 +73,8 @@ struct BuildConfirmationWindow : Window {
 		switch (widget) {
 			case WID_BC_OK:
 				if (pt.y <= (int)GetWidget<NWidgetViewport>(WID_BC_OK)->current_y / 2) {
+					_thd.selstart = selstart;
+					_thd.selend = selend;
 					ConfirmPlacingObject();
 					ToolbarSelectLastTool();
 				} else {
@@ -91,8 +99,8 @@ struct BuildConfirmationWindow : Window {
 	{
 		this->DrawWidgets();
 
-		DrawButtonFrame(0, 0, this->width, this->height / 2 - 1, STR_BUTTON_OK);
+		DrawButtonFrame(0, 0, this->width - 1, this->height / 2 - 2, STR_BUTTON_OK);
-		DrawButtonFrame(0, this->height / 2, this->width, this->height / 2, STR_BUTTON_CANCEL);
+		DrawButtonFrame(0, this->height / 2, this->width - 1, this->height / 2 - 1, STR_BUTTON_CANCEL);
 	}
 
 	void DrawButtonFrame(int x, int y, int w, int h, int str)

src/viewport.cpp

@@ -3149,6 +3149,8 @@ EventState VpHandlePlaceSizingDrag()
 		return ES_HANDLED;
 	}
 
+	ShowBuildConfirmationWindow(); // This will also remember tile selection, so it's okay for the4 code below
+
 	/* mouse button released..
 	 * keep the selected tool, but reset it to the original mode. */
 	_special_mouse_mode = WSM_NONE;
@@ -3167,7 +3169,6 @@ EventState VpHandlePlaceSizingDrag()
 	SetTileSelectSize(1, 1);
 
 place_mouseup:
-	ShowBuildConfirmationWindow();
 	return ES_HANDLED;
 }
 
@@ -3176,7 +3177,6 @@ void ConfirmPlacingObject()
 	Window *w = _thd.GetCallbackWnd();
 	if (w == NULL) ResetObjectToPlace();
 
-
 	w->OnPlaceMouseUp(_thd.select_method, _thd.select_proc, _thd.selend, TileVirtXY(_thd.selstart.x, _thd.selstart.y), TileVirtXY(_thd.selend.x, _thd.selend.y));
 }
 
@@ -3257,6 +3257,7 @@ void ResetObjectToPlace()
 		_last_selected_window_number = _thd.window_number;
 	}
 	SetObjectToPlace(SPR_CURSOR_MOUSE, PAL_NONE, HT_NONE, WC_MAIN_WINDOW, 0);
+	HideBuildConfirmationWindow();
 	MoveAllHiddenWindowsBackToScreen();
 }