@@ -50,6 +50,7 @@ func (cli *Client) CopyToContainer(ctx context.Context, containerID, dstPath str

 	}

 	defer ensureReaderClosed(response)

+	// TODO this code converts non-error status-codes (e.g., "204 No Content") into an error; verify if this is the desired behavior

 	if response.statusCode != http.StatusOK {

 		return fmt.Errorf("unexpected status code from daemon: %d", response.statusCode)

 	}

@@ -69,6 +70,7 @@ func (cli *Client) CopyFromContainer(ctx context.Context, containerID, srcPath s

 		return nil, types.ContainerPathStat{}, wrapResponseError(err, response, "container:path", containerID+":"+srcPath)

 	}

+	// TODO this code converts non-error status-codes (e.g., "204 No Content") into an error; verify if this is the desired behavior

 	if response.statusCode != http.StatusOK {

 		return nil, types.ContainerPathStat{}, fmt.Errorf("unexpected status code from daemon: %d", response.statusCode)

 	}

@@ -121,6 +121,7 @@ func TestCopyToContainerNotFoundError(t *testing.T) {

 	}

 }

+// TODO TestCopyToContainerNotStatusOKError expects a non-error status-code ("204 No Content") to produce an error; verify if this is the desired behavior

 func TestCopyToContainerNotStatusOKError(t *testing.T) {

 	client := &Client{

 		client: newMockClient(errorMock(http.StatusNoContent, "No content")),

@@ -200,6 +201,7 @@ func TestCopyFromContainerNotFoundError(t *testing.T) {

 	}

 }

+// TODO TestCopyFromContainerNotStatusOKError expects a non-error status-code ("204 No Content") to produce an error; verify if this is the desired behavior

 func TestCopyFromContainerNotStatusOKError(t *testing.T) {

 	client := &Client{

 		client: newMockClient(errorMock(http.StatusNoContent, "No content")),

@@ -3,12 +3,12 @@ package client // import "github.com/docker/docker/client"

 import (

 	"context"

 	"io"

-	"net/http"

 	"net/url"

 	"strings"

 	"github.com/docker/distribution/reference"

 	"github.com/docker/docker/api/types"

+	"github.com/docker/docker/errdefs"

 )

 // ImagePull requests the docker host to pull an image from a remote registry.

@@ -35,7 +35,7 @@ func (cli *Client) ImagePull(ctx context.Context, refStr string, options types.I

 	}

 	resp, err := cli.tryImageCreate(ctx, query, options.RegistryAuth)

-	if resp.statusCode == http.StatusUnauthorized && options.PrivilegeFunc != nil {

+	if errdefs.IsUnauthorized(err) && options.PrivilegeFunc != nil {

 		newAuthHeader, privilegeErr := options.PrivilegeFunc()

 		if privilegeErr != nil {

 			return nil, privilegeErr

@@ -4,11 +4,11 @@ import (

 	"context"

 	"errors"

 	"io"

-	"net/http"

 	"net/url"

 	"github.com/docker/distribution/reference"

 	"github.com/docker/docker/api/types"

+	"github.com/docker/docker/errdefs"

 )

 // ImagePush requests the docker host to push an image to a remote registry.

@@ -36,7 +36,7 @@ func (cli *Client) ImagePush(ctx context.Context, image string, options types.Im

 	query.Set("tag", tag)

 	resp, err := cli.tryImagePush(ctx, name, query, options.RegistryAuth)

-	if resp.statusCode == http.StatusUnauthorized && options.PrivilegeFunc != nil {

+	if errdefs.IsUnauthorized(err) && options.PrivilegeFunc != nil {

 		newAuthHeader, privilegeErr := options.PrivilegeFunc()

 		if privilegeErr != nil {

 			return nil, privilegeErr

@@ -4,12 +4,12 @@ import (

 	"context"

 	"encoding/json"

 	"fmt"

-	"net/http"

 	"net/url"

 	"github.com/docker/docker/api/types"

 	"github.com/docker/docker/api/types/filters"

 	"github.com/docker/docker/api/types/registry"

+	"github.com/docker/docker/errdefs"

 )

 // ImageSearch makes the docker host to search by a term in a remote registry.

@@ -29,7 +29,7 @@ func (cli *Client) ImageSearch(ctx context.Context, term string, options types.I

 	}

 	resp, err := cli.tryImageSearch(ctx, query, options.RegistryAuth)

-	if resp.statusCode == http.StatusUnauthorized && options.PrivilegeFunc != nil {

+	if errdefs.IsUnauthorized(err) && options.PrivilegeFunc != nil {

 		newAuthHeader, privilegeErr := options.PrivilegeFunc()

 		if privilegeErr != nil {

 			return results, privilegeErr

@@ -3,7 +3,6 @@ package client // import "github.com/docker/docker/client"

 import (

 	"context"

 	"encoding/json"

-	"net/http"

 	"net/url"

 	"github.com/docker/docker/api/types"

@@ -15,9 +14,6 @@ import (

 func (cli *Client) RegistryLogin(ctx context.Context, auth types.AuthConfig) (registry.AuthenticateOKBody, error) {

 	resp, err := cli.post(ctx, "/auth", url.Values{}, auth, nil)

-	if resp.statusCode == http.StatusUnauthorized {

-		return registry.AuthenticateOKBody{}, unauthorizedError{err}

-	}

 	if err != nil {

 		return registry.AuthenticateOKBody{}, err

 	}

@@ -4,11 +4,11 @@ import (

 	"context"

 	"encoding/json"

 	"io"

-	"net/http"

 	"net/url"

 	"github.com/docker/distribution/reference"

 	"github.com/docker/docker/api/types"

+	"github.com/docker/docker/errdefs"

 	"github.com/pkg/errors"

 )

@@ -78,7 +78,7 @@ func (cli *Client) tryPluginPull(ctx context.Context, query url.Values, privileg

 func (cli *Client) checkPluginPermissions(ctx context.Context, query url.Values, options types.PluginInstallOptions) (types.PluginPrivileges, error) {

 	resp, err := cli.tryPluginPrivileges(ctx, query, options.RegistryAuth)

-	if resp.statusCode == http.StatusUnauthorized && options.PrivilegeFunc != nil {

+	if errdefs.IsUnauthorized(err) && options.PrivilegeFunc != nil {

 		// todo: do inspect before to check existing name before checking privileges

 		newAuthHeader, privilegeErr := options.PrivilegeFunc()

 		if privilegeErr != nil {