Make error handling more robust

1 files changed, 72 insertions, 78 deletions

diff --git a/trash.go b/trash.go
index 126d3fe..37a48ab 100644
--- a/trash.go
+++ b/trash.go
@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"io/fs"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -11,104 +12,81 @@ import (
 	"time"
 )
 
-func cp(srcRoot string, dstRoot string) (err error) {
-	defer func() {
+func cpEntry(srcDirEntry os.DirEntry, src, dst string) error {
+	switch srcDirEntry.Type() {
+	case 0: // regular file
+		srcF, err := os.Open(src)
 		if err != nil {
-			os.RemoveAll(dstRoot)
+			return err
 		}
-	}()
-
-	type roDir struct {
-		path string
-		mode os.FileMode
-	}
-	var roDirs []roDir
-
-	srcRoot = filepath.Clean(srcRoot)
-	if err := filepath.WalkDir(srcRoot, func(src string, d os.DirEntry, err error) error {
+		defer srcF.Close()
+		stat, err := srcF.Stat()
 		if err != nil {
 			return err
 		}
-		dst := filepath.Join(dstRoot, strings.TrimPrefix(src, srcRoot))
-		switch d.Type() {
-		case 0: // regular file
-			srcF, err := os.Open(src)
-			if err != nil {
-				return err
-			}
-			defer srcF.Close()
-			stat, err := srcF.Stat()
-			if err != nil {
-				return err
-			}
-			dstF, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_EXCL, stat.Mode().Perm())
-			if err != nil {
-				return err
-			}
-			defer dstF.Close()
-			if _, err := io.Copy(dstF, srcF); err != nil {
-				return err
-			}
-			if err := dstF.Close(); err != nil {
-				return err
-			}
-			return nil
-		case os.ModeSymlink:
-			linkTarget, err := os.Readlink(src)
-			if err != nil {
-				return err
-			}
-			return os.Symlink(linkTarget, dst)
-		case os.ModeDir:
-			stat, err := d.Info()
-			if err != nil {
-				return err
-			}
-			perm := stat.Mode().Perm()
-			if perm&0300 != 0300 {
-				roDirs = append(roDirs, roDir{dst, perm})
-				// Make sure we can create directory contents.
-				perm |= 0300
-			}
-			return os.MkdirAll(dst, perm)
-		default:
-			return fmt.Errorf("unknown file type %s", d.Type())
+		dstF, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_EXCL, stat.Mode().Perm())
+		if err != nil {
+			return err
 		}
-	}); err != nil {
-		return err
-	}
-	// Iterate backwards to process directory contents before the parent directory.
-	for i := len(roDirs) - 1; i >= 0; i-- {
-		dir := roDirs[i]
-		if err := os.Chmod(dir.path, dir.mode); err != nil {
+		defer dstF.Close()
+		if _, err := io.Copy(dstF, srcF); err != nil {
 			return err
 		}
+		return dstF.Close()
+	case os.ModeSymlink:
+		linkTarget, err := os.Readlink(src)
+		if err != nil {
+			return err
+		}
+		return os.Symlink(linkTarget, dst)
+	case os.ModeDir:
+		stat, err := srcDirEntry.Info()
+		if err != nil {
+			return err
+		}
+		entries, err := os.ReadDir(src)
+		if err != nil {
+			return err
+		}
+		if err := os.Mkdir(dst, 0700); err != nil {
+			return err
+		}
+		for _, entry := range entries {
+			name := entry.Name()
+			if err := cpEntry(entry, filepath.Join(src, name), filepath.Join(dst, name)); err != nil {
+				return err
+			}
+		}
+		return os.Chmod(dst, stat.Mode().Perm())
+	default:
+		return fmt.Errorf("unknown file type %s", srcDirEntry.Type())
 	}
-	return nil
 }
 
-func mv(src, dst string) error {
-	if err := os.Rename(src, dst); err == nil {
-		return nil
+func cp(src, dst string) error {
+	stat, err := os.Lstat(src)
+	if err != nil {
+		return err
 	}
-	if err := cp(src, dst); err != nil {
+	if err := cpEntry(fs.FileInfoToDirEntry(stat), src, dst); err != nil {
+		os.RemoveAll(dst)
 		return err
 	}
-	return os.RemoveAll(src)
+	return nil
 }
 
-func trashFile(fileName, trash, now string) (err error) {
+func writeTrashInfo(fileName, trash, now string) (_ string, err error) {
 	absPath, err := filepath.Abs(fileName)
 	if err != nil {
-		return fmt.Errorf("%s: find absolute path: %s", fileName, err)
+		return "", fmt.Errorf("find absolute path: %s", err)
 	}
 	info, err := os.CreateTemp(filepath.Join(trash, "info"), filepath.Base(fileName)+"."+now+".*.trashinfo")
 	if err != nil {
-		return fmt.Errorf("%s: create trashinfo: %s", fileName, err)
+		return "", fmt.Errorf("create trashinfo: %s", err)
 	}
 	defer func() {
-		info.Close()
 		if err != nil {
+			info.Close()
 			os.Remove(info.Name())
 		}
 	}()
@@ -120,15 +98,31 @@ func trashFile(fileName, trash, now string) (err error) {
 Path=%s
 DeletionDate=%s
 `,
-		filepath.Join(escapedPath...),
+		strings.Join(escapedPath, string(filepath.Separator)),
 		now)
 	if err != nil {
-		return fmt.Errorf("%s: write trashinfo: %s", fileName, err)
+		return "", fmt.Errorf("write trashinfo: %s", err)
 	}
 	if err := info.Close(); err != nil {
-		return fmt.Errorf("%s: write trashinfo: %s", fileName, err)
+		return "", fmt.Errorf("write trashinfo: %s", err)
+	}
+	return info.Name(), err
+}
+
+func trashFile(fileName, trash, now string) error {
+	trashInfo, err := writeTrashInfo(fileName, trash, now)
+	if err != nil {
+		return fmt.Errorf("%s: %s", fileName, err)
+	}
+	dst := filepath.Join(trash, "files", strings.TrimSuffix(filepath.Base(trashInfo), ".trashinfo"))
+	if err := os.Rename(fileName, dst); err == nil {
+		return nil
+	}
+	if err := cp(fileName, dst); err != nil {
+		os.Remove(trashInfo)
+		return fmt.Errorf("%s: %s", fileName, err)
 	}
-	if err := mv(fileName, filepath.Join(trash, "files", strings.TrimSuffix(filepath.Base(info.Name()), ".trashinfo"))); err != nil {
+	if err := os.RemoveAll(fileName); err != nil {
 		return fmt.Errorf("%s: %s", fileName, err)
 	}
 	return nil