- added --enable-localdune option

- added two types of library-check:
  a) normal search for lib in default-path (for a global installation
     some time in the future)
  b) a check for a signs of a compiled lib in a local
     Dune-installation if "localdune" is enabled. This is by no chance
     a strict check but what we want for local development

[[Imported from SVN: r251]]

m4/dune.m4

@@ -3,8 +3,7 @@
 
 # TODO
 #
-# use pkg-config later? Maybe not really worth it, because only one -I is
-# needed right now...
+# - use pkg-config if --enable-localdune is not provided
 
 #   #export PKG_CONFIG_LIBDIR=$with_dune/dune
 #  #PKG_CHECK_MODULES(DUNE, dune)  
@@ -20,9 +19,14 @@ AC_DEFUN([DUNE_PATH_DUNE],[
   AC_ARG_WITH(dune,
     AC_HELP_STRING([--with-dune=PATH],[directory with Dune inside]))
 
+  AC_ARG_ENABLE(localdune,
+    AC_HELP_STRING([--enable-localdune],[use Dune-headers/lib]))
+
   # backup of flags
   ac_save_CPPFLAGS="$CPPFLAGS"
+  ac_save_LIBS="$LIBS"
   CPPFLAGS=""
+  LIBS=""
 
   # is a directory set?
   if test "x$with_dune" != x ; then
@@ -46,18 +50,67 @@ AC_DEFUN([DUNE_PATH_DUNE],[
     [HAVE_DUNE=0]
   )
 
+  # did we find the headers?
+  if test x$HAVE_DUNE = x1 ; then
+    # check for library
+    #
+    # for the devel-mode, we're searching for a .la-file in the
+    # with-dune-directory, otherwise we'll really test for a lib
+    # (installed in a proper directory!)      
+
+    if test x"$enable_localdune" != xyes ; then
+      ## normal test
+
+      # !!! should be pkg-config later (which would save the special
+      # header-check above)
+      # !!! insert symbol defined in the libdune
+      AC_CHECK_LIB(dune, ,[HAVE_DUNE=1],[HAVE_DUNE=0])
+
+    else
+      ## special test for a local installation
+      ac_save_LDFLAGS="$LDFLAGS"
+      	
+      if test x$DUNEROOT != x ; then
+        # have a look into the dune-dir
+	LDFLAGS="$LDFLAGS -L$DUNEROOT/dune/lib"
+
+	# only check for a .la-file
+	if test -s $DUNEROOT/dune/lib/libdune.la ; then
+	    DUNE_LDFLAGS="-L$DUNEROOT/dune/lib"
+	    echo found libdune.la, setting LDFLAGS to $DUNE_LDFLAGS
+
+	    # provide arguments like normal lib-check
+	    LIBS="-ldune"
+	    HAVE_DUNE=1
+	else
+	    AC_MSG_ERROR([localdune is enabled but libdune.la was not found. Please compile the library or set a correct --with-dune])
+	fi
+      else
+	  AC_MSG_ERROR([--enable-localdune needs a --with-dune-parameter!])
+      fi
+
+      # reset variable
+      LDFLAGS="$ac_save_LDFLAGS"
+    fi
+  fi
+
   # did we succeed?
   if test x$HAVE_DUNE = x1 ; then
     AC_SUBST(DUNE_CPPFLAGS, $DUNE_CPPFLAGS)
-    AC_DEFINE(HAVE_DUNE, 1, [Define to 1 if dune-headers were found])
+    AC_SUBST(DUNE_LDFLAGS, $DUNE_LDFLAGS)
+    AC_SUBST(DUNE_LIBS, $LIBS)
+    AC_DEFINE(HAVE_DUNE, 1, [Define to 1 if dune was found])
 
     # add to global list
     DUNE_PKG_CPPFLAGS="$DUNE_PKG_CPPFLAGS $DUNE_CPPFLAGS"
+    DUNE_PKG_LIBS="$DUNE_PKG_LIBS $LIBS"
+    DUNE_PKG_LDFLAGS="$DUNE_PKG_LDFLAGS $DUNE_LDFLAGS"
   fi
 
   # reset previous flags
   CPPFLAGS="$ac_save_CPPFLAGS"
+  LIBS="$ac_save_LIBS"
 
   # restore previous language settings (leave C++)
   AC_LANG_POP([C++])
-])
+])
\ No newline at end of file