@@ -13,7 +13,6 @@ import (

 	"github.com/docker/docker/api/server/httputils"

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

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

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

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

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

 	"github.com/docker/docker/pkg/ioutils"

@@ -46,9 +45,6 @@ func (s *imageRouter) postCommit(ctx context.Context, w http.ResponseWriter, r *

 	if err != nil && err != io.EOF { //Do not fail if body is empty.

 		return err

 	}

-	if c == nil {

-		c = &container.Config{}

-	}

 	commitCfg := &backend.ContainerCommitConfig{

 		ContainerCommitConfig: types.ContainerCommitConfig{

@@ -396,7 +396,8 @@ func BuildFromConfig(config *container.Config, changes []string) (*container.Con

 	}

 	dispatchRequest := newDispatchRequest(b, dockerfile.EscapeToken, nil, newBuildArgs(b.options.BuildArgs), newStagesBuildResults())

-	dispatchRequest.state.runConfig = config

+	// We make mutations to the configuration, ensure we have a copy

+	dispatchRequest.state.runConfig = copyRunConfig(config)

 	dispatchRequest.state.imageID = config.Image

 	for _, cmd := range commands {

 		err := dispatch(dispatchRequest, cmd)

@@ -149,6 +149,10 @@ func (daemon *Daemon) Commit(name string, c *backend.ContainerCommitConfig) (str

 		defer daemon.containerUnpause(container)

 	}

+	if c.MergeConfigs && c.Config == nil {

+		c.Config = container.Config

+	}

+

 	newConfig, err := dockerfile.BuildFromConfig(c.Config, c.Changes)

 	if err != nil {

 		return "", err

@@ -121,11 +121,19 @@ func (s *DockerSuite) TestCommitChange(c *check.C) {

 		"test", "test-commit")

 	imageID = strings.TrimSpace(imageID)

+	// The ordering here is due to `PATH` being overridden from the container's

+	// ENV.  On windows, the container doesn't have a `PATH` ENV variable so

+	// the ordering is the same as the cli.

+	expectedEnv := "[PATH=/foo DEBUG=true test=1]"

+	if testEnv.DaemonPlatform() == "windows" {

+		expectedEnv = "[DEBUG=true test=1 PATH=/foo]"

+	}

+

 	prefix, slash := getPrefixAndSlashFromDaemonPlatform()

 	prefix = strings.ToUpper(prefix) // Force C: as that's how WORKDIR is normalized on Windows

 	expected := map[string]string{

 		"Config.ExposedPorts": "map[8080/tcp:{}]",

-		"Config.Env":          "[DEBUG=true test=1 PATH=/foo]",

+		"Config.Env":          expectedEnv,

 		"Config.Labels":       "map[foo:bar]",

 		"Config.Cmd":          "[/bin/sh]",

 		"Config.WorkingDir":   prefix + slash + "opt",

new file mode 100644

@@ -0,0 +1,47 @@

+package image

+

+import (

+	"context"

+	"testing"

+

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

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

+	"github.com/docker/docker/integration/util/request"

+	"github.com/stretchr/testify/assert"

+	"github.com/stretchr/testify/require"

+)

+

+func TestCommitInheritsEnv(t *testing.T) {

+	defer setupTest(t)()

+	client := request.NewAPIClient(t)

+	ctx := context.Background()

+

+	createResp1, err := client.ContainerCreate(ctx, &container.Config{Image: "busybox"}, nil, nil, "")

+	require.NoError(t, err)

+

+	commitResp1, err := client.ContainerCommit(ctx, createResp1.ID, types.ContainerCommitOptions{

+		Changes:   []string{"ENV PATH=/bin"},

+		Reference: "test-commit-image",

+	})

+	require.NoError(t, err)

+

+	image1, _, err := client.ImageInspectWithRaw(ctx, commitResp1.ID)

+	require.NoError(t, err)

+

+	expectedEnv1 := []string{"PATH=/bin"}

+	assert.Equal(t, expectedEnv1, image1.Config.Env)

+

+	createResp2, err := client.ContainerCreate(ctx, &container.Config{Image: image1.ID}, nil, nil, "")

+	require.NoError(t, err)

+

+	commitResp2, err := client.ContainerCommit(ctx, createResp2.ID, types.ContainerCommitOptions{

+		Changes:   []string{"ENV PATH=/usr/bin:$PATH"},

+		Reference: "test-commit-image",

+	})

+	require.NoError(t, err)

+

+	image2, _, err := client.ImageInspectWithRaw(ctx, commitResp2.ID)

+	require.NoError(t, err)

+	expectedEnv2 := []string{"PATH=/usr/bin:/bin"}

+	assert.Equal(t, expectedEnv2, image2.Config.Env)

+}