add command history and history expansion to lua console

Adds an optional dependency on the readline library.

CMakeLists.txt

@@ -88,6 +88,7 @@ option(ENABLE_PANDORA "Add support for the OpenPandora by deactivating libvorbis
 option(ENABLE_SDL_GPU "Enable building with SDL_gpu (experimental" OFF)
 option(ENABLE_BOOST_FILESYSTEM "Enable building with the boost filesystem and boost locale code" ON)
 option(ENABLE_LIBPNG "Enable support for writing png files (screenshots, images)" ON)
+option(ENABLE_READLINE "Enable using readline for history in lua console" OFF)
 
 if(NOT DEFINED ENABLE_DISPLAY_REVISION)
 	# Test whether the code is used in a repository if not autorevision will
@@ -605,6 +606,13 @@ if(ENABLE_GAME)
 	else(ENABLE_LIBPNG AND PNG_FOUND)
 		message("Could not find lib PNG. Disabling support for writing PNG images.")	
 	endif(ENABLE_LIBPNG AND PNG_FOUND)
+
+	find_package( READLINE )
+	if(ENABLE_READLINE AND READLINE_FOUND)
+		add_definitions(-DHAVE_READLINE)
+	else(ENABLE_READLINE AND READLINE_FOUND)
+		message("Could not find readline. Disabling support for command history in lua console.")
+	endif(ENABLE_READLINE AND READLINE_FOUND)
 endif(ENABLE_GAME)
 
 if(ENABLE_POT_UPDATE_TARGET)

INSTALL

@@ -38,6 +38,7 @@ These libraries are optional dependencies that enable additional features:
 
  libdbus-1 (used for desktop notifications)
  libpng (save images as pngs, otherwise only bmp is possible)
+ readline (for command history and history expansion in the lua console)
 
 As a temporary compatibility measure, it is possible to build the game without requiring boost filesystem or boost locale, using libintl for translations instead. The cost is that wesnoth won't support UTF-8 in filepaths on all platforms.
 For this, target filesystem.cpp and gettext.cpp instead of filesystem_boost.cpp and gettext_boost.cpp. For scons/cmake the "boost filesystem" option toggles these.

SConstruct

@@ -106,6 +106,7 @@ opts.AddVariables(
     BoolVariable("fast", "Make scons faster at cost of less precise dependency tracking.", False),
     BoolVariable("lockfile", "Create a lockfile to prevent multiple instances of scons from being run at the same time on this working copy.", False),
     BoolVariable("OS_ENV", "Forward the entire OS environment to scons", False),
+    BoolVariable("readline", "Clear to disable readline support in lua console", False),
     BoolVariable("sdl2", "Build with SDL2 support (experimental!)", False)
     )
 
@@ -414,6 +415,10 @@ if env["prereqs"]:
         if env["png"]:
             client_env.Append(CPPDEFINES = ["HAVE_LIBPNG"])
 
+        env["readline"] = env["readline"] and conf.CheckLib("readline")
+        if env["readline"]:
+            client_env.Append(CPPDEFINES = ["HAVE_READLINE"])
+
     if env["forum_user_handler"]:
         flags = env.ParseFlags("!mysql_config --libs --cflags")
         try: # Some versions of mysql_config add -DNDEBUG but we don't want it