Merge pull request #10209 from filecoin-project/fix-check-backupfile

fix: cli: error if backup file already exists

cli/backup.go

@@ -61,6 +61,10 @@ func BackupCmd(repoFlag string, rt repo.RepoType, getApi BackupApiFn) *cli.Comma
 			return xerrors.Errorf("expanding file path: %w", err)
 		}
 
+		if _, err := os.Stat(fpath); !os.IsNotExist(err) {
+			return xerrors.Errorf("backup file %s already exists. Overwriting it will corrupt the file, please specify another file name", fpath)
+		}
+
 		out, err := os.OpenFile(fpath, os.O_CREATE|os.O_WRONLY, 0644)
 		if err != nil {
 			return xerrors.Errorf("opening backup file %s: %w", fpath, err)
@@ -87,7 +91,12 @@ func BackupCmd(repoFlag string, rt repo.RepoType, getApi BackupApiFn) *cli.Comma
 		}
 		defer closer()
 
-		err = api.CreateBackup(ReqContext(cctx), cctx.Args().First())
+		backupPath := cctx.Args().First()
+		if _, err := os.Stat(backupPath); !os.IsNotExist(err) {
+			return xerrors.Errorf("backup file %s already exists. Overwriting it will corrupt the file, please specify another file name", backupPath)
+		}
+
+		err = api.CreateBackup(ReqContext(cctx), backupPath)
 		if err != nil {
 			return err
 		}