Merge branch 'master' into jgrpp

# Conflicts:
#	src/core/strong_typedef_type.hpp
#	src/gfx.cpp
#	src/group_cmd.cpp
#	src/industry_cmd.cpp
#	src/map_func.h
#	src/newgrf_debug_gui.cpp
#	src/order_cmd.cpp
#	src/pathfinder/follow_track.hpp
#	src/rail_cmd.cpp
#	src/road_cmd.cpp
#	src/road_gui.cpp
#	src/saveload/saveload.cpp
#	src/screenshot.cpp
#	src/smallmap_gui.cpp
#	src/station_cmd.cpp
#	src/strings.cpp
#	src/tile_type.h
#	src/timetable_gui.cpp
#	src/town_cmd.cpp
#	src/train_cmd.cpp
#	src/viewport.cpp

src/story_gui.cpp

@@ -25,6 +25,7 @@
 #include "company_base.h"
 #include "tilehighlight_func.h"
 #include "vehicle_base.h"
+#include "core/backup_type.hpp"
 
 #include "widgets/story_widget.h"
 
@@ -697,8 +698,7 @@ public:
 		DrawPixelInfo tmp_dpi;
 		if (!FillDrawPixelInfo(&tmp_dpi, fr.left, fr.top, fr.Width(), fr.Height())) return;
 
-		DrawPixelInfo *old_dpi = _cur_dpi;
-		_cur_dpi = &tmp_dpi;
+		AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
 
 		/* Draw content (now coordinates given to Draw** are local to the new clipping region). */
 		fr = fr.Translate(-fr.left, -fr.top);
@@ -757,9 +757,6 @@ public:
 				default: NOT_REACHED();
 			}
 		}
-
-		/* Restore clipping region. */
-		_cur_dpi = old_dpi;
 	}
 
 	void UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *fill, Dimension *resize) override