[PATCH] configure.ac: try -lpthread in $LIBS instead of $CFLAGS

["Rainer M. Canavan" <git@canavan.de>]

Some linkers, namely the one on IRIX are rather strict concerning the order or
arguments for symbol resolution, i.e. no libraries listed before objects or
other libraries on the command line are considered for symbol resolution. That
means that -lpthread can't work if it's put in CFLAGS, because it will not be
considered for resolving pthread_key_create in conftest.o. Use $LIBS instead.

Signed-off-by: Rainer Canavan <git@canavan.de>
---
 configure.ac | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index fd22d41..1f55009 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1149,7 +1149,12 @@ elif test -z "$PTHREAD_CFLAGS"; then
   # would then trigger compiler warnings on every single file we compile.
   for opt in "" -mt -pthread -lpthread; do
      old_CFLAGS="$CFLAGS"
-     CFLAGS="$opt $CFLAGS"
+     old_LIBS="$LIBS"
+     case "$opt" in
+        -l*)  LIBS="$opt $LIBS" ;;
+        *)    CFLAGS="$opt $CFLAGS" ;;
+     esac
+
      AC_MSG_CHECKING([for POSIX Threads with '$opt'])
      AC_LINK_IFELSE([PTHREADTEST_SRC],
 	[AC_MSG_RESULT([yes])
@@ -1161,6 +1166,7 @@ elif test -z "$PTHREAD_CFLAGS"; then
 	],
 	[AC_MSG_RESULT([no])])
       CFLAGS="$old_CFLAGS"
+      LIBS="$old_LIBS"
   done
   if test $threads_found != yes; then
     AC_CHECK_LIB([pthread], [pthread_create],
-- 
2.6.2