BUILD: Tie the SDL_net version to the SDL version

This means that when using SDL 1.2 we use SDL_net 1.2, but when
using SDL 2 we now use SLD_net 2 as well. Both versions work
properly and there is not code change needed in ScummVM.

This change is because SDL_net depends on SDL, and using
SDL_net 1.2 with SDL 2 means we can end up needing to link with
both the SDL and SDL2 libraries.

backends/networking/sdl_net/client.cpp

@@ -25,7 +25,7 @@
 #include "backends/networking/sdl_net/client.h"
 #include "backends/networking/sdl_net/localwebserver.h"
 #include "common/memstream.h"
-#include <SDL/SDL_net.h>
+#include <SDL_net.h>
 
 namespace Networking {
 

backends/networking/sdl_net/localwebserver.cpp

@@ -29,7 +29,7 @@
 #include "common/system.h"
 #include "common/timer.h"
 #include "common/translation.h"
-#include <SDL/SDL_net.h>
+#include <SDL_net.h>
 #include <common/config-manager.h>
 
 #ifdef POSIX

backends/platform/sdl/sdl.cpp

@@ -61,12 +61,11 @@
 #endif
 
 #ifdef USE_SDL_NET
-#include <SDL/SDL_net.h>
+#include <SDL_net.h>
 #endif
 
 #if SDL_VERSION_ATLEAST(2, 0, 0)
-#include <SDL2/SDL.h>
-#include <SDL2/SDL_clipboard.h>
+#include <SDL_clipboard.h>
 #endif
 
 OSystem_SDL::OSystem_SDL()

configure

@@ -3355,10 +3355,30 @@ case $_backend in
 		case $_sdlversion in
 			2.0.*)
 				add_line_to_config_mk "USE_SDL2 = 1"
+				append_var SDL_NET_LIBS "-lSDL2_net"
 				;;
 			*)
+				append_var SDL_NET_LIBS "-lSDL_net"
 				;;
 		esac
+
+		# Check for SDL_Net
+		echocheck "SDL_Net"
+		if test "$_sdlnet" = auto ; then
+			_sdlnet=no
+			cat > $TMPC << EOF
+#include "SDL_net.h"
+int main(int argc, char *argv[]) { SDLNet_Init(); return 0; }
+EOF
+			cc_check $LIBS $INCLUDES $SDL_NET_CFLAGS $SDL_NET_LIBS && _sdlnet=yes
+		fi
+		if test "$_sdlnet" = yes ; then
+			append_var LIBS "$SDL_NET_LIBS"
+			append_var INCLUDES "$SDL_NET_CFLAGS"
+		fi
+		define_in_config_if_yes "$_sdlnet" 'USE_SDL_NET'
+		echo "$_sdlnet"
+		
 		;;
 esac
 
@@ -4134,25 +4154,6 @@ EOF
 	;;
 esac
 
-#
-# Check for SDL_Net
-#
-echocheck "SDL_Net"
-if test "$_sdlnet" = auto ; then
-	_sdlnet=no
-	cat > $TMPC << EOF
-#include "SDL/SDL_net.h"
-int main(int argc, char *argv[]) { SDLNet_Init(); return 0; }
-EOF
-	cc_check $LIBS $INCLUDES $SDL_NET_CFLAGS $SDL_NET_LIBS -lSDL_net && _sdlnet=yes
-fi
-if test "$_sdlnet" = yes ; then
-	append_var LIBS "$SDL_NET_LIBS -lSDL_net"
-	append_var INCLUDES "$SDL_NET_CFLAGS"
-fi
-define_in_config_if_yes "$_sdlnet" 'USE_SDL_NET'
-echo "$_sdlnet"
-
 #
 # Check for libcurl to be present
 #