Merge branch 'master' into jgrpp

# Conflicts:
#	cmake/CompileFlags.cmake
#	src/cargomonitor.cpp
#	src/core/CMakeLists.txt
#	src/economy.cpp
#	src/landscape.cpp
#	src/linkgraph/flowmapper.cpp
#	src/linkgraph/linkgraph_gui.cpp
#	src/linkgraph/linkgraphschedule.cpp
#	src/misc_gui.cpp
#	src/newgrf_generic.cpp
#	src/newgrf_storage.cpp
#	src/rail_gui.cpp
#	src/saveload/afterload.cpp
#	src/saveload/station_sl.cpp
#	src/script/script_gui.cpp
#	src/station_cmd.cpp
#	src/station_gui.cpp
#	src/string_func.h
#	src/terraform_cmd.cpp

src/querystring_gui.h

@@ -14,6 +14,8 @@
 #include "textbuf_gui.h"
 #include "window_gui.h"
 
+#include <optional>
+
 /**
  * Data stored about a string that can be modified in the GUI
  */
@@ -27,7 +29,7 @@ struct QueryString {
 	int ok_button;      ///< Widget button of parent window to simulate when pressing OK in OSK.
 	int cancel_button;  ///< Widget button of parent window to simulate when pressing CANCEL in OSK.
 	Textbuf text;
-	const char *orig;
+	std::optional<std::string> orig;
 	bool handled;
 
 	/**
@@ -35,18 +37,10 @@ struct QueryString {
 	 * @param size Maximum size in bytes.
 	 * @param chars Maximum size in chars.
 	 */
-	QueryString(uint16 size, uint16 chars = UINT16_MAX) : ok_button(ACTION_NOTHING), cancel_button(ACTION_DESELECT), text(size, chars), orig(nullptr)
+	QueryString(uint16 size, uint16 chars = UINT16_MAX) : ok_button(ACTION_NOTHING), cancel_button(ACTION_DESELECT), text(size, chars)
 	{
 	}
 
-	/**
-	 * Make sure everything gets freed.
-	 */
-	~QueryString()
-	{
-		free(this->orig);
-	}
-
 public:
 	void DrawEditBox(const Window *w, int wid) const;
 	void ClickEditBox(Window *w, Point pt, int wid, int click_count, bool focus_changed);