updated restore backup warning message and changed archive.Extract to ignore irregular files

tools/archive/create_test.go

@@ -48,7 +48,7 @@ func TestCreateSuccess(t *testing.T) {
 		t.Fatalf("Expected zip with name %q, got %q", zipName, name)
 	}
 
-	expectedSize := int64(405)
+	expectedSize := int64(544)
 	if size := info.Size(); size != expectedSize {
 		t.Fatalf("Expected zip with size %d, got %d", expectedSize, size)
 	}
@@ -116,5 +116,10 @@ func createTestDir(t *testing.T) string {
 		f.Close()
 	}
 
+	// symbolic link
+	if err := os.Symlink(filepath.Join(dir, "test"), filepath.Join(dir, "test_symlink")); err != nil {
+		t.Fatal(err)
+	}
+
 	return dir
 }

tools/archive/extract.go

@@ -9,7 +9,11 @@ import (
 	"strings"
 )
 
-// Extract extracts the zip archive at src to dest.
+// Extract extracts the zip archive at "src" to "dest".
+//
+// Note that only dirs and regular files will be extracted.
+// Symbolic links, named pipes, sockets, or any other irregular files
+// are skipped because they come with too many edge cases and ambiguities.
 func Extract(src, dest string) error {
 	zr, err := zip.OpenReader(src)
 	if err != nil {
@@ -46,11 +50,12 @@ func extractFile(zipFile *zip.File, basePath string) error {
 	}
 	defer r.Close()
 
+	// allow only dirs or regular files
 	if zipFile.FileInfo().IsDir() {
 		if err := os.MkdirAll(path, os.ModePerm); err != nil {
 			return err
 		}
-	} else {
+	} else if zipFile.FileInfo().Mode().IsRegular() {
 		// ensure that the file path directories are created
 		if err := os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
 			return err

tools/archive/extract_test.go

@@ -37,7 +37,7 @@ func TestExtractSuccess(t *testing.T) {
 	defer os.RemoveAll(extractedPath)
 
 	// zip testDir content (with exclude)
-	if err := archive.Create(testDir, zipPath, "a/b/c", "test", "sub2"); err != nil {
+	if err := archive.Create(testDir, zipPath, "a/b/c", "test2", "sub2"); err != nil {
 		t.Fatalf("Failed to create archive: %v", err)
 	}
 
@@ -64,8 +64,9 @@ func TestExtractSuccess(t *testing.T) {
 		t.Fatalf("Failed to read the extracted dir: %v", walkErr)
 	}
 
+	// (note: symbolic links and other regular files should be missing)
 	expectedFiles := []string{
-		filepath.Join(extractedPath, "test2"),
+		filepath.Join(extractedPath, "test"),
 		filepath.Join(extractedPath, "a/test"),
 		filepath.Join(extractedPath, "a/b/sub1"),
 	}