From: Robert Schwebel <r.schwebel@pengutronix.de>
Subject: libtheora: fix configure.ac to work with cross scenario for sdl

This is https://trac.xiph.org/ticket/1466

The current test in configure.ac mixes up two different methods (hand
written plus pkg-config). This patch changes the mechanics towards
proper pkg-config usage. In return, we get a cleaned up cross scenario
with no build-system leakage.

This patch fixes the SDL test.

Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>

---
 configure.ac |   29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

Index: libtheora-1.0/configure.ac
===================================================================
--- libtheora-1.0.orig/configure.ac
+++ libtheora-1.0/configure.ac
@@ -312,13 +312,32 @@ if test "${HAVE_VORBIS}" = "yes"; then
     AC_SUBST(VORBIS_LIBS)
 fi
 
+
 dnl check for SDL
-HAVE_SDL=no
+AC_MSG_CHECKING([for sdl])
+AC_ARG_ENABLE(sdl,
+    AS_HELP_STRING([--enable-sdl], [enable SDL @<:@default=yes@:>@]),
+        [case "$enableval" in
+        y | yes) HAVE_SDL=yes ;;
+        *) HAVE_SDL=no ;;
+        esac],
+    [HAVE_SDL=yes])
+AC_MSG_RESULT([${HAVE_SDL}])
+AM_CONDITIONAL(HAVE_SDL, [test "$HAVE_SDL" = "yes"])
+if test "${HAVE_SDL}" = "yes"; then
+    AC_DEFINE(HAVE_SDL, 1, [sdl])
+
+    REQUIRES_SDL="sdl >= 1.2.13"
+    AC_SUBST(REQUIRES_SDL)
+    PKG_CHECK_MODULES([SDL],
+          [${REQUIRES_SDL}],
+          [],
+          [AC_MSG_ERROR([*** ${REQUIRES_SDL} not found by pkg-config on your system])]
+    )
+    AC_SUBST(SDL_CFLAGS)
+    AC_SUBST(SDL_LIBS)
+fi
 
-AM_PATH_SDL(,[
-  HAVE_SDL=yes
-  SDL_LIBS=`$SDL_CONFIG --libs`
-],AC_MSG_WARN([*** Unable to find SDL -- Not compiling example players ***]))
 
 dnl check for OSS
 HAVE_OSS=no