@@ -15,7 +15,6 @@ import (

 	"github.com/docker/docker/api"

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

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

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

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

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

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

@@ -27,8 +26,6 @@ import (

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

 	"github.com/docker/docker/pkg/progress"

 	"github.com/docker/docker/pkg/streamformatter"

-	"github.com/docker/go-connections/nat"

-	dockerspec "github.com/moby/docker-image-spec/specs-go/v1"

 	"github.com/opencontainers/go-digest"

 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

 	"github.com/pkg/errors"

@@ -370,7 +367,7 @@ func (ir *imageRouter) getImagesByName(ctx context.Context, w http.ResponseWrite

 		return errdefs.InvalidParameter(errors.New("conflicting options: manifests and platform options cannot both be set"))

 	}

-	imageInspect, err := ir.backend.ImageInspect(ctx, vars["name"], backend.ImageInspectOpts{

+	resp, err := ir.backend.ImageInspect(ctx, vars["name"], backend.ImageInspectOpts{

 		Manifests: manifests,

 		Platform:  platform,

 	})

@@ -378,6 +375,14 @@ func (ir *imageRouter) getImagesByName(ctx context.Context, w http.ResponseWrite

 		return err

 	}

+	// inspectResponse preserves fields in the response that have an

+	// "omitempty" in the OCI spec, but didn't omit such fields in

+	// legacy responses before API v1.50.

+	imageInspect := &inspectCompatResponse{

+		InspectResponse: resp,

+		legacyConfig:    legacyConfigFields["current"],

+	}

+

 	// Make sure we output empty arrays instead of nil. While Go nil slice is functionally equivalent to an empty slice,

 	// it matters for the JSON representation.

 	if imageInspect.RepoTags == nil {

@@ -405,14 +410,7 @@ func (ir *imageRouter) getImagesByName(ctx context.Context, w http.ResponseWrite

 		imageInspect.Descriptor = nil

 	}

 	if versions.LessThan(version, "1.50") {

-		type imageInspectLegacy struct {

-			imagetypes.InspectResponse

-			LegacyConfig *container.Config `json:"Config"`

-		}

-		return httputils.WriteJSON(w, http.StatusOK, imageInspectLegacy{

-			InspectResponse: *imageInspect,

-			LegacyConfig:    dockerOCIImageConfigToContainerConfig(*imageInspect.Config),

-		})

+		imageInspect.legacyConfig = legacyConfigFields["v1.49"]

 	}

 	return httputils.WriteJSON(w, http.StatusOK, imageInspect)

@@ -598,27 +596,3 @@ func validateRepoName(name reference.Named) error {

 	}

 	return nil

 }

-

-// FIXME(thaJeztah): this is a copy of dockerOCIImageConfigToContainerConfig in daemon/containerd: https://github.com/moby/moby/blob/6b617699c500522aa6526cfcae4558333911b11f/daemon/containerd/imagespec.go#L107-L128

-func dockerOCIImageConfigToContainerConfig(cfg dockerspec.DockerOCIImageConfig) *container.Config {

-	exposedPorts := make(nat.PortSet, len(cfg.ExposedPorts))

-	for k, v := range cfg.ExposedPorts {

-		exposedPorts[nat.Port(k)] = v

-	}

-

-	return &container.Config{

-		Entrypoint:   cfg.Entrypoint,

-		Env:          cfg.Env,

-		Cmd:          cfg.Cmd,

-		User:         cfg.User,

-		WorkingDir:   cfg.WorkingDir,

-		ExposedPorts: exposedPorts,

-		Volumes:      cfg.Volumes,

-		Labels:       cfg.Labels,

-		ArgsEscaped:  cfg.ArgsEscaped, //nolint:staticcheck // Ignore SA1019. Need to keep it in image.

-		StopSignal:   cfg.StopSignal,

-		Healthcheck:  cfg.Healthcheck,

-		OnBuild:      cfg.OnBuild,

-		Shell:        cfg.Shell,

-	}

-}

new file mode 100644

@@ -0,0 +1,88 @@

+// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:

+//go:build go1.23

+

+package image

+

+import (

+	"encoding/json"

+	"maps"

+

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

+)

+

+// legacyConfigFields defines legacy image-config fields to include in

+// API responses on older API versions.

+var legacyConfigFields = map[string]map[string]any{

+	// Legacy fields for API v1.49 and lower. These fields are deprecated

+	// and omitted in newer API versions; see https://github.com/moby/moby/pull/48457

+	"v1.49": {

+		"AttachStderr": false,

+		"AttachStdin":  false,

+		"AttachStdout": false,

+		"Cmd":          nil,

+		"Domainname":   "",

+		"Entrypoint":   nil,

+		"Env":          nil,

+		"Hostname":     "",

+		"Image":        "",

+		"Labels":       nil,

+		"OnBuild":      nil,

+		"OpenStdin":    false,

+		"StdinOnce":    false,

+		"Tty":          false,

+		"User":         "",

+		"Volumes":      nil,

+		"WorkingDir":   "",

+	},

+	// Legacy fields for current API versions (v1.50 and up). These fields

+	// did not have an "omitempty" and were always included in the response,

+	// even if not set; see https://github.com/moby/moby/issues/50134

+	"current": {

+		"Cmd":        nil,

+		"Entrypoint": nil,

+		"Env":        nil,

+		"Labels":     nil,

+		"OnBuild":    nil,

+		"User":       "",

+		"Volumes":    nil,

+		"WorkingDir": "",

+	},

+}

+

+// inspectCompatResponse is a wrapper around [image.InspectResponse] with a

+// custom marshal function for legacy [api/types/container.Config} fields

+// that have been removed, or did not have omitempty.

+type inspectCompatResponse struct {

+	*image.InspectResponse

+	legacyConfig map[string]any

+}

+

+// MarshalJSON implements a custom marshaler to include legacy fields

+// in API responses.

+func (ir *inspectCompatResponse) MarshalJSON() ([]byte, error) {

+	type tmp *image.InspectResponse

+	base, err := json.Marshal((tmp)(ir.InspectResponse))

+	if err != nil {

+		return nil, err

+	}

+	if len(ir.legacyConfig) == 0 {

+		return base, nil

+	}

+

+	type resp struct {

+		*image.InspectResponse

+		Config map[string]any

+	}

+

+	var merged resp

+	err = json.Unmarshal(base, &merged)

+	if err != nil {

+		return base, nil

+	}

+

+	// prevent mutating legacyConfigFields.

+	cfg := maps.Clone(ir.legacyConfig)

+	maps.Copy(cfg, merged.Config)

+	merged.Config = cfg

+	return json.Marshal(merged)

+}

new file mode 100644

@@ -0,0 +1,74 @@

+package image

+

+import (

+	"encoding/json"

+	"testing"

+

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

+	dockerspec "github.com/moby/docker-image-spec/specs-go/v1"

+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

+	"gotest.tools/v3/assert"

+	is "gotest.tools/v3/assert/cmp"

+)

+

+func TestInspectResponse(t *testing.T) {

+	tests := []struct {

+		doc          string

+		cfg          *ocispec.ImageConfig

+		legacyConfig map[string]any

+		expected     string

+	}{

+		{

+			doc:      "empty",

+			expected: `null`,

+		},

+		{

+			doc: "no legacy config",

+			cfg: &ocispec.ImageConfig{

+				Cmd:        []string{"/bin/sh"},

+				StopSignal: "SIGQUIT",

+			},

+			expected: `{"Cmd":["/bin/sh"],"StopSignal":"SIGQUIT"}`,

+		},

+		{

+			doc: "api < v1.50",

+			cfg: &ocispec.ImageConfig{

+				Cmd:        []string{"/bin/sh"},

+				StopSignal: "SIGQUIT",

+			},

+			legacyConfig: legacyConfigFields["v1.49"],

+			expected:     `{"AttachStderr":false,"AttachStdin":false,"AttachStdout":false,"Cmd":["/bin/sh"],"Domainname":"","Entrypoint":null,"Env":null,"Hostname":"","Image":"","Labels":null,"OnBuild":null,"OpenStdin":false,"StdinOnce":false,"StopSignal":"SIGQUIT","Tty":false,"User":"","Volumes":null,"WorkingDir":""}`,

+		},

+		{

+			doc: "api >= v1.50",

+			cfg: &ocispec.ImageConfig{

+				Cmd:        []string{"/bin/sh"},

+				StopSignal: "SIGQUIT",

+			},

+			legacyConfig: legacyConfigFields["current"],

+			expected:     `{"Cmd":["/bin/sh"],"Entrypoint":null,"Env":null,"Labels":null,"OnBuild":null,"StopSignal":"SIGQUIT","User":"","Volumes":null,"WorkingDir":""}`,

+		},

+	}

+	for _, tc := range tests {

+		t.Run(tc.doc, func(t *testing.T) {

+			imgInspect := &image.InspectResponse{}

+			if tc.cfg != nil {

+				// Verify that fields that are set override the legacy values,

+				// or appended if not part of the legacy values.

+				imgInspect.Config = &dockerspec.DockerOCIImageConfig{

+					ImageConfig: *tc.cfg,

+				}

+			}

+			out, err := json.Marshal(&inspectCompatResponse{

+				InspectResponse: imgInspect,

+				legacyConfig:    tc.legacyConfig,

+			})

+			assert.NilError(t, err)

+

+			var outMap struct{ Config json.RawMessage }

+			err = json.Unmarshal(out, &outMap)

+			assert.NilError(t, err)

+			assert.Check(t, is.Equal(string(outMap.Config), tc.expected))

+		})

+	}

+}

@@ -3138,13 +3138,7 @@ func (s *DockerCLIBuildSuite) TestBuildClearCmd(c *testing.T) {

    CMD []`))

 	cmd := inspectFieldJSON(c, name, "Config.Cmd")

-	// OCI types specify `omitempty` JSON annotation which doesn't serialize

-	// empty arrays and the Cmd will not be present at all.

-	if testEnv.UsingSnapshotter() {

-		assert.Check(c, is.Equal(cmd, "null"))

-	} else {

-		assert.Check(c, is.Equal(cmd, "[]"))

-	}

+	assert.Check(c, is.Equal(cmd, "null"))

 }

 func (s *DockerCLIBuildSuite) TestBuildEmptyCmd(c *testing.T) {