Fix and cleanup PTHREAD linking.

Add in missing $PTHREAD_LIBS to all backends that can make use of it.
Rename --enable-fork-process to --enable-pthread to maatch internal
logic.  Also, stop linking in pthreads needlessly if its been
disabled.

ChangeLog

@@ -1,3 +1,10 @@
+2009-05-04 Chris Bagwell <cbagwell-guest at users.alioth.debian.org>
+	* acinclude.m4: Rename --enable-fork-process to --enable-pthreads
+	to match internal usage. Stop linking in pthread when disabled.
+	* backend/Makefile.am: Add $PTHREAD_LIBS to all backends that
+	include sanei_thread.
+	* Makefile.am: Add new ChangeLog-1.0.20 to distribution list.
+
 2009-05-03 m. allan noah <kitno455 at gmail dot com>
 	* ChangeLog-1.0.20, Makefile.in: ChangeLog from 1.0.20 release
 	* configure, configure.in: version 1.0.21cvs

Makefile.am

@@ -17,6 +17,7 @@ EXTRA_DIST = ChangeLog-1.0.0 ChangeLog-1.0.1  ChangeLog-1.0.2 \
  ChangeLog-1.0.7 ChangeLog-1.0.8 ChangeLog-1.0.9 ChangeLog-1.0.10 \
  ChangeLog-1.0.12 ChangeLog-1.0.13 ChangeLog-1.0.14 ChangeLog-1.0.15 \
  ChangeLog-1.0.16 ChangeLog-1.0.17 ChangeLog-1.0.18 ChangeLog-1.0.19 \
+ ChangeLog-1.0.20 \
  $(PACKAGE).lsm
 
 #

acinclude.m4

@@ -226,18 +226,24 @@ AC_DEFUN([SANE_CHECK_PTHREAD],
   *)
     use_pthread=no
   esac
+  have_pthread=no
 
   #
   # now that we have the systems preferences, we check
   # the user
-  AC_ARG_ENABLE( [fork-process],
-    AC_HELP_STRING([--enable-fork-process],
-                   [use fork instead of pthread (default=no for MacOS X, yes for everything else)]),
+
+  AC_ARG_ENABLE([pthread],
+    AC_HELP_STRING([--enable-pthread],
+                   [use pthread instead of fork (default=yes for MacOS X, no for everything else)]),
     [
-      if test $enableval != yes ; then
+      if test $enableval = yes ; then
         use_pthread=yes
+      else
+        use_pthread=no
       fi
     ])
+
+  if test $use_pthread = yes ; then
   AC_CHECK_HEADERS(pthread.h,
     [
        AC_CHECK_LIB(pthread, pthread_create, PTHREAD_LIBS="-lpthread")
@@ -246,17 +252,21 @@ AC_DEFUN([SANE_CHECK_PTHREAD],
        LIBS="$LIBS $PTHREAD_LIBS"
        AC_CHECK_FUNCS([pthread_create pthread_kill pthread_join pthread_detach pthread_cancel pthread_testcancel],
 	,[ have_pthread=no; use_pthread=no ])
-        LIBS="$save_LIBS"
+       LIBS="$save_LIBS"
     ],)
-  AC_SUBST(PTHREAD_LIBS)
+  fi
  
   if test $use_pthread = yes ; then
     AC_DEFINE_UNQUOTED(USE_PTHREAD, "$use_pthread",
                    [Define if pthreads should be used instead of forked processes.])
+  else
+    dnl Reset library in case it was found but we are not going to use it.
+    PTHREAD_LIBS=""
   fi
   if test "$have_pthread" = "yes" ; then
     CPPFLAGS="${CPPFLAGS} -D_REENTRANT"
   fi
+  AC_SUBST(PTHREAD_LIBS)
   AC_MSG_CHECKING([whether to enable pthread support])
   AC_MSG_RESULT([$have_pthread])
   AC_MSG_CHECKING([whether to use pthread instead of fork])