tests: verify that symlinks work

integration_tests/example_filesystems/normal/6hL2fPVB2aMSh4-UoDn5Kw==

@@ -0,0 +1 @@
+3-HZSwv99agoWgTErV0YFQ==

integration_tests/example_filesystems/normal/TBIgdfhDKwkXVTnWLVzFSg==

@@ -0,0 +1 @@
+/tTXhw8tmmz4PK9YG21Whug==/Qe8z0HUArb5bZJjUqEo2Nw==/wv68UB9DLF9OfAcxgRKKtQ==/9No5n3deBUGa-BsvPRi3DQ==

integration_tests/example_filesystems_test.go

@@ -3,6 +3,7 @@ package integration_tests
 // Mount example filesystems and check that the file "status.txt" is there
 
 import (
+	"path/filepath"
 	"io/ioutil"
 	"os"
 	"testing"
@@ -12,8 +13,10 @@ const statusTxtContent = "It works!\n"
 
 // checkStatusTxt - read file "filename" and verify that it contains
 // "It works!\n"
-func checkStatusTxt(t *testing.T, filename string) {
+func checkExampleContent(t *testing.T, dir string) {
-	contentBytes, err := ioutil.ReadFile(filename)
+	// Check regular file
+	statusFile := filepath.Join(dir, "status.txt")
+	contentBytes, err := ioutil.ReadFile(statusFile)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -21,6 +24,24 @@ func checkStatusTxt(t *testing.T, filename string) {
 	if content != statusTxtContent {
 		t.Errorf("Unexpected content: %s\n", content)
 	}
+	// Check relative symlink
+	symlink := filepath.Join(dir, "rel")
+	target, err := os.Readlink(symlink)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if target != "status.txt" {
+		t.Errorf("Unexpected link target: %s\n", target)
+	}
+	// Check absolute symlink
+	symlink = filepath.Join(dir, "abs")
+	target, err = os.Readlink(symlink)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if target != "/a/b/c/d" {
+		t.Errorf("Unexpected link target: %s\n", target)
+	}
 }
 
 // Test example_filesystems/normal
@@ -33,11 +54,11 @@ func TestExampleFsNormal(t *testing.T) {
 		t.Fatal(err)
 	}
 	mount(cDir, pDir, "-extpass", "echo test")
-	checkStatusTxt(t, pDir+"status.txt")
+	checkExampleContent(t, pDir)
 	unmount(pDir)
 	mount(cDir, pDir, "-masterkey", "74676e34-0b47c145-00dac61a-17a92316-"+
 		"bb57044c-e205b71f-65f4fdca-7cabd4b3", "-diriv=false")
-	checkStatusTxt(t, pDir+"status.txt")
+	checkExampleContent(t, pDir)
 	unmount(pDir)
 	err = os.Remove(pDir)
 	if err != nil {