Mesa (master): autoconf: Fix build of dri symbols test to not manually link expat.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 36473395f1e7574fc22fd4f5210ad6a8def76d91
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=36473395f1e7574fc22fd4f5210ad6a8def76d91

Author: Eric Anholt <eric at anholt.net>
Date:   Wed Jan 18 11:27:24 2012 -0800

autoconf: Fix build of dri symbols test to not manually link expat.

AC_CHECK_LIB has this nasty behavior, like the cflags tests, of
automatically putting the tested value into the global LIBS on
success.  This caused -lexpat to end up in LIBS, but without the
--with-expat dir, so my 32-bit build on a 64 system using expat from a
custom prefix could only find the system expat and fail to link on the
one current consumer of the LIBS variable: the dri driver test link.

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 configure.ac |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/configure.ac b/configure.ac
index c76af5b..b15a4bc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1231,8 +1231,10 @@ if test "x$enable_dri" = xyes; then
             EXPAT_LIB="-L$withval/$LIB_DIR -lexpat"
             ])
         AC_CHECK_HEADER([expat.h],[],[AC_MSG_ERROR([Expat required for DRI.])])
+	save_LIBS="$LIBS"
         AC_CHECK_LIB([expat],[XML_ParserCreate],[],
             [AC_MSG_ERROR([Expat required for DRI.])])
+	LIBS="$save_LIBS"
     fi
 
     # libdrm is required for all except swrast