If thread-safety-constructor is enabled, link against pthreads not stubs

Only really makes a difference if pthreads is not in libc.

Fixes: #162

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>

configure.ac

@@ -222,9 +222,6 @@ xyes)
 	;;
 esac
 
-AC_CHECK_LIB(c, pthread_self, [thrstubs="no"], [thrstubs="yes"])
-AM_CONDITIONAL(THRSTUBS, test x$thrstubs = xyes)
-
 # XXX incomplete, please fill this in
 if test x$xthreads = xyes ; then
     case $host_os in
@@ -245,6 +242,14 @@ fi
 AC_SUBST(XTHREADLIB)
 AC_SUBST(XTHREAD_CFLAGS)
 
+if test "x$USE_THREAD_SAFETY_CONSTRUCTOR" = "xyes"; then
+   USE_THREAD_LIBS="$XTHREADLIB"
+fi
+AC_SUBST(USE_THREAD_LIBS)
+
+AC_CHECK_LIB(c, pthread_self, [thrstubs="no"], [thrstubs="yes"], [$USE_THREAD_LIBS])
+AM_CONDITIONAL(THRSTUBS, test x$thrstubs = xyes)
+
 AC_CHECK_FUNC(poll, [AC_DEFINE(USE_POLL, 1, [poll() function is available])], )
 
 #

src/Makefile.am

@@ -371,6 +371,7 @@ libX11_la_LIBADD = \
 	$(USE_I18N_LIBS) \
 	$(USE_XCMS_LIBS) \
 	$(USE_XKB_LIBS) \
+	$(USE_THREAD_LIBS) \
 	$(X11_LIBS)
 
 preprocess: $(patsubst %.c,%.ii,$(libX11_la_SOURCES))