Merge branch 'master' into jgrpp

# Conflicts:
#	.github/workflows/ci-build.yml
#	.github/workflows/release-linux.yml
#	.github/workflows/release-macos.yml
#	.github/workflows/release-source.yml
#	.github/workflows/release.yml
#	CMakeLists.txt
#	COMPILING.md
#	src/ai/ai_core.cpp
#	src/ai/ai_gui.cpp
#	src/bridge_gui.cpp
#	src/company_gui.cpp
#	src/console_cmds.cpp
#	src/core/CMakeLists.txt
#	src/core/smallmap_type.hpp
#	src/disaster_vehicle.h
#	src/effectvehicle_base.h
#	src/fontcache.cpp
#	src/game/game_core.cpp
#	src/game/game_gui.cpp
#	src/gamelog.cpp
#	src/gamelog_internal.h
#	src/group_gui.cpp
#	src/linkgraph/linkgraph.h
#	src/misc.cpp
#	src/network/core/config.h
#	src/network/core/udp.cpp
#	src/network/network_chat_gui.cpp
#	src/network/network_content_gui.cpp
#	src/network/network_gui.cpp
#	src/newgrf.cpp
#	src/newgrf_gui.cpp
#	src/newgrf_profiling.cpp
#	src/newgrf_profiling.h
#	src/object_gui.cpp
#	src/openttd.cpp
#	src/openttd.h
#	src/order_gui.cpp
#	src/os/windows/font_win32.cpp
#	src/rail_gui.cpp
#	src/road.cpp
#	src/road_gui.cpp
#	src/saveload/afterload.cpp
#	src/saveload/saveload.h
#	src/script/api/script_controller.cpp
#	src/script/api/script_roadtypelist.cpp
#	src/script/script_config.cpp
#	src/script/script_config.hpp
#	src/script/script_instance.cpp
#	src/script/script_scanner.cpp
#	src/script/squirrel.cpp
#	src/script/squirrel_helper.hpp
#	src/settings_gui.cpp
#	src/settings_internal.h
#	src/settings_type.h
#	src/table/settings/network_private_settings.ini
#	src/timetable_gui.cpp
#	src/vehicle.cpp
#	src/vehicle_base.h
#	src/window_gui.h

src/widget_type.h

@@ -814,7 +814,30 @@ public:
 		}
 	}
 
-	int GetScrolledRowFromWidget(int clickpos, const Window * const w, int widget, int padding = 0) const;
+	int GetScrolledRowFromWidget(int clickpos, const Window * const w, int widget, int padding = 0, int line_height = -1) const;
+
+	/**
+	 * Return an iterator pointing to the element of a scrolled widget that a user clicked in.
+	 * @param container   Container of elements represented by the scrollbar.
+	 * @param clickpos    Vertical position of the mouse click (without taking scrolling into account).
+	 * @param w           The window the click was in.
+	 * @param widget      Widget number of the widget clicked in.
+	 * @param padding     Amount of empty space between the widget edge and the top of the first row. Default value is \c 0.
+	 * @param line_height Height of a single row. A negative value means using the vertical resize step of the widget.
+	 * @return Iterator to the element clicked at. If clicked at a wrong position, returns as interator to the end of the container.
+	 */
+	template <typename Tcontainer>
+	typename Tcontainer::iterator GetScrolledItemFromWidget(Tcontainer &container, int clickpos, const Window * const w, int widget, int padding = 0, int line_height = -1) const
+	{
+		assert(this->GetCount() == container.size()); // Scrollbar and container size must match.
+		int row = this->GetScrolledRowFromWidget(clickpos, w, widget, padding, line_height);
+		if (row == INT_MAX) return std::end(container);
+
+		typename Tcontainer::iterator it = std::begin(container);
+		std::advance(it, row);
+		return it;
+	}
+
 	EventState UpdateListPositionOnKeyPress(int &list_position, uint16 keycode) const;
 };