if len(p) == 0 {
		return 0, r.setErr(nil, false)
	}
	r.mu.Lock()
	defer r.mu.Unlock()
	if err := r.err; err != nil {
		if err == io.EOF {
			err = ErrWriteOnClosed
		}
		return 0, err
	}
	wrote := 0
	for len(p) > 0 {
		n, err = r.write(p)
		wrote += n
		if !r.block || err == nil {
			break
		}
		err = r.setErr(err, true)

func (s *Scanner) advance(n int) bool {
	if n < 0 {
		s.setErr(ErrNegativeAdvance)
		return false
	}
	if n > s.end-s.start {
		s.setErr(ErrAdvanceTooFar)
		return false
	}
	s.start += n
	return true
}

// setErr records the first error encountered.
func (s *Scanner) setErr(err error) {
	if s.err == nil || s.err == io.EOF {
		s.err = err
	}
}

	// Save listing...
	go func() {
		if err := saver.saveMetaCacheStream(listCtx, &meta, saveCh); err != nil {
			meta.setErr(err.Error())
		}
		cancel()
	}()

	// Do listing...
	go func(o listPathOptions) {
		err := z.listMerged(listCtx, o, inCh)
		if err != nil {
			meta.setErr(err.Error())
		}
		o.debugln("listAndSave: listing", o.ID, "finished with ", err)
	}(*o)

	cancel context.CancelFunc
}

func (m *metaCacheRPC) setErr(err string) {
	m.mu.Lock()
	defer m.mu.Unlock()
	meta := *m.meta
	if meta.status != scanStateError {
		meta.error = err
		meta.status = scanStateError
	} else {
		// An error is already set.
		return
	}
	meta, _ = m.o.updateMetacacheListing(meta, m.rpc)
	*m.meta = meta
}

// getErr will return an error if the listing failed.

		})
	}
}

func verifyTestcaseOutput(t *testing.T, cmd *cobra.Command, c testcase) {
	t.Helper()

	var out bytes.Buffer
	cmd.SetArgs(c.args)
	cmd.SetOut(&out)
	cmd.SetErr(&out)
	cmd.SilenceUsage = true
	if c.namespace != "" {
		namespace = c.namespace
	}

	fErr := cmd.Execute()
	output := out.String()

	if c.expectedException {
		if fErr == nil {

            System.setOut(new PrintStream(outStream, true));
            final PrintStream originalErrStream = System.err;
            final ByteArrayOutputStream errStream = new ByteArrayOutputStream();
            System.setErr(new PrintStream(errStream, true));
            try {
                final String resourceName = params == null ? null : params.get(ExtractData.RESOURCE_NAME_KEY);

	}

	if c.configDumps == nil {
		c.configDumps = map[string][]byte{}
	}

	var out bytes.Buffer
	rootCmd := Cmd(ctx)
	rootCmd.SetArgs(c.args)

	rootCmd.SetOut(&out)
	rootCmd.SetErr(&out)

	if c.namespace != "" {
		describeNamespace = c.namespace
	}

	fErr := rootCmd.Execute()
	output := out.String()

	if c.expectedOutput != "" && c.expectedOutput != output {

			validateCmd.SilenceUsage = true
			validateCmd.SetArgs(c.args)

			// capture output to keep test logs clean
			var out bytes.Buffer
			validateCmd.SetOut(&out)
			validateCmd.SetErr(&out)

			err := validateCmd.Execute()
			if (err != nil) != c.wantError {
				t.Errorf("unexpected validate return status: got %v want %v: \nerr=%v",
					err != nil, c.wantError, err)
			}

            stderr.setLogLevel(LocationAwareLogger.INFO_INT);
            System.setOut(new LoggingOutputStream(s -> stdout.info("[stdout] " + s)).printStream());
            System.setErr(new LoggingOutputStream(s -> stderr.warn("[stderr] " + s)).printStream());
            // no need to set them back, this is already handled by MessageUtils.systemUninstall() above
        }
    }

				retErr = err
				healingLogIf(ctx, err)
				continue
			}
			// Check if bucket is object locked.
			lr, err = globalBucketObjectLockSys.Get(bucket)
			if err != nil {
				retErr = err
				healingLogIf(ctx, err)
				continue
			}
			rcfg, err = getReplicationConfig(ctx, bucket)
			if err != nil {
				retErr = err
				healingLogIf(ctx, err)
				continue