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/dock_gui.cpp

@@ -25,6 +25,7 @@
 #include "hotkeys.h"
 #include "gui.h"
 #include "zoom_func.h"
+#include "core/backup_type.hpp"
 
 #include "widgets/dock_widget.h"
 
@@ -544,15 +545,13 @@ public:
 				Axis axis = widget == WID_BDD_X ? AXIS_X : AXIS_Y;
 
 				if (FillDrawPixelInfo(&tmp_dpi, r.left, r.top, r.Width(), r.Height())) {
-					DrawPixelInfo *old_dpi = _cur_dpi;
-					_cur_dpi = &tmp_dpi;
+					AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
 					int x = (r.Width()  - ScaleSpriteTrad(96)) / 2;
 					int y = (r.Height() - ScaleSpriteTrad(64)) / 2;
 					int x1 = ScaleSpriteTrad(63);
 					int x2 = ScaleSpriteTrad(31);
 					DrawShipDepotSprite(x + (axis == AXIS_X ? x1 : x2), y + ScaleSpriteTrad(17), axis, DEPOT_PART_NORTH);
 					DrawShipDepotSprite(x + (axis == AXIS_X ? x2 : x1), y + ScaleSpriteTrad(33), axis, DEPOT_PART_SOUTH);
-					_cur_dpi = old_dpi;
 				}
 				break;
 			}