@@ -425,13 +425,17 @@ func (ir *imageRouter) getImagesByName(ctx context.Context, w http.ResponseWrite

 			"DockerVersion": imageInspect.DockerVersion, //nolint:staticcheck // ignore SA1019: field is deprecated, but still included in response when present.

 			"Author":        imageInspect.Author,

 		}))

+

+		// preserve fields in the image Config that have an "omitempty"

+		// in the OCI spec, but weren't omitted in API v1.51 and lower.

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

-			legacyOptions = append(legacyOptions, compat.WithExtraFields(legacyConfigFields["v1.49"]))

+			legacyOptions = append(legacyOptions, compat.WithExtraFields(map[string]any{

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

+			}))

 		} else {

-			// 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.

-			legacyOptions = append(legacyOptions, compat.WithExtraFields(legacyConfigFields["v1.50-v1.51"]))

+			legacyOptions = append(legacyOptions, compat.WithExtraFields(map[string]any{

+				"Config": legacyConfigFields["v1.50-v1.51"],

+			}))

 		}

 	}

@@ -1,12 +1,5 @@

 package image

-import (

-	"encoding/json"

-	"maps"

-

-	"github.com/moby/moby/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{

@@ -31,9 +24,9 @@ var legacyConfigFields = map[string]map[string]any{

 		"Volumes":      nil,

 		"WorkingDir":   "",

 	},

-	// Legacy fields for current API versions (v1.50 and v1.52). 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

+	// Legacy fields for API v1.50 and v1.51. 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

 	"v1.50-v1.51": {

 		"Cmd":        nil,

 		"Entrypoint": nil,

@@ -45,41 +38,3 @@ var legacyConfigFields = map[string]map[string]any{

 		"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)

-}

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

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

 	"github.com/moby/moby/api/types/image"

+	"github.com/moby/moby/v2/daemon/internal/compat"

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

 	"gotest.tools/v3/assert"

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

@@ -59,10 +60,11 @@ func TestInspectResponse(t *testing.T) {

 					ImageConfig: *tc.cfg,

 				}

 			}

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

-				InspectResponse: imgInspect,

-				legacyConfig:    tc.legacyConfig,

-			})

+			legacyConfigResponse := compat.Wrap(imgInspect, compat.WithExtraFields(map[string]any{

+				"Config": tc.legacyConfig,

+			}))

+

+			out, err := json.Marshal(&legacyConfigResponse)

 			assert.NilError(t, err)

 			var outMap struct{ Config json.RawMessage }