Fix typo: use links variable for retrieving symlinks.

Add tests.

unionfs/cachingfs.go

@@ -161,7 +161,7 @@ func (me *CachingFileSystem) GetXAttr(name string, attr string) ([]byte, fuse.St
 }
 
 func (me *CachingFileSystem) Readlink(name string) (string, fuse.Status) {
-	r := me.attributes.Get(name).(*linkResponse)
+	r := me.links.Get(name).(*linkResponse)
 	return r.linkContent, r.Status
 }
 

unionfs/cachingfs_test.go

+package unionfs
+
+import (
+	"os"
+	"github.com/hanwen/go-fuse/fuse"
+	"fmt"
+	"log"
+	"syscall"
+	"testing"
+)
+
+var _ = fmt.Print
+var _ = log.Print
+
+
+func modeMapEq(m1, m2 map[string]uint32) bool {
+	if len(m1) != len(m2) {
+		return false
+	}
+
+	for k, v := range m1 {
+		val, ok := m2[k]
+		if !ok || val != v {
+			return false
+		}
+	}
+	return true
+}
+
+func TestCachingFs(t *testing.T) {
+	wd := fuse.MakeTempDir()
+	defer os.RemoveAll(wd)
+	
+	fs := fuse.NewLoopbackFileSystem(wd)
+	cfs := NewCachingFileSystem(fs, 0)
+
+	os.Mkdir(wd+"/orig", 0755)
+	fi, code := cfs.GetAttr("orig")
+	if !code.Ok() {
+		t.Fatal("GetAttr failure", code)
+	} 
+	if !fi.IsDirectory() {
+		t.Error("unexpected attr", fi)
+	}
+	
+	os.Symlink("orig", wd+"/symlink")
+
+	val, code := cfs.Readlink("symlink")
+	if val != "orig" {
+		t.Error("unexpected readlink", val)
+	}
+	if !code.Ok() {
+		t.Error("code !ok ", code)
+	}
+
+	stream, code := cfs.OpenDir("")
+	if !code.Ok() {
+		t.Fatal("Readdir fail", code)
+	}
+
+	results := make(map[string]uint32)
+	for v := range stream {
+		results[v.Name] = v.Mode &^ 07777
+	}
+	expected := map[string]uint32{
+		"symlink": syscall.S_IFLNK,
+		"orig": fuse.S_IFDIR,
+	}
+	if !modeMapEq(results, expected) {
+		t.Error("Unexpected readdir result", results, expected)
+	}
+}
+

unionfs/unionfs_test.go

@@ -102,7 +102,7 @@ func mapEq(m1, m2 map[string]bool) bool {
 	}
 
 	for k, v := range m1 {
-		ok, val := m2[k]
+		val, ok := m2[k]
 		if !ok || val != v {
 			return false
 		}