Fixes vacation regression

- Some archive files can have a relative reference to the destination
directory i.e. ./ . These files should still be able to be decompressed
so logic has been added to see if the destination path of the file is
the destination directory itself.

Author: ForestEckhardt

vacation/vacation.go

@@ -409,10 +409,10 @@ func (z ZipArchive) Decompress(destination string) error {
 }
 
 // This function checks to see that the given path is within the destination
-// directory
+// directory or it is the destination directory itself i.e. ./
 func checkExtractPath(filePath string, destination string) error {
 	destpath := filepath.Join(destination, filePath)
-	if !strings.HasPrefix(destpath, filepath.Clean(destination)+string(os.PathSeparator)) {
+	if !strings.HasPrefix(destpath, filepath.Clean(destination)+string(os.PathSeparator)) && destpath != filepath.Clean(destination) {
 		return fmt.Errorf("illegal file path %q: the file path does not occur within the destination directory", filePath)
 	}
 	return nil

vacation/vacation_tar_gzip_test.go

@@ -35,6 +35,12 @@ func testVacationTarGzip(t *testing.T, context spec.G, it spec.S) {
 			gw := gzip.NewWriter(buffer)
 			tw := tar.NewWriter(gw)
 
+			// Some archive files will make a relative top level path directory these
+			// should still successfully decompress.
+			Expect(tw.WriteHeader(&tar.Header{Name: "./", Mode: 0755, Typeflag: tar.TypeDir})).To(Succeed())
+			_, err = tw.Write(nil)
+			Expect(err).NotTo(HaveOccurred())
+
 			Expect(tw.WriteHeader(&tar.Header{Name: "some-dir", Mode: 0755, Typeflag: tar.TypeDir})).To(Succeed())
 			_, err = tw.Write(nil)
 			Expect(err).NotTo(HaveOccurred())

vacation/vacation_zip_test.go

@@ -42,6 +42,11 @@ func testVacationZip(t *testing.T, context spec.G, it spec.S) {
 			_, err = symlink.Write([]byte(filepath.Join("some-dir", "some-other-dir", "some-file")))
 			Expect(err).NotTo(HaveOccurred())
 
+			// Some archive files will make a relative top level path directory these
+			// should still successfully decompress.
+			_, err = zw.Create("./")
+			Expect(err).NotTo(HaveOccurred())
+
 			_, err = zw.Create("some-dir/")
 			Expect(err).NotTo(HaveOccurred())