From b03ad66a930ba2135e5114a6e611c63a7e0cd61f Mon Sep 17 00:00:00 2001
From: Keith Zantow <kzantow@gmail.com>
Date: Tue, 15 Nov 2022 11:58:35 -0500
Subject: [PATCH] fix: unset metadata type when no metadata is present decoding
 an SBOM

Signed-off-by: Keith Zantow <kzantow@gmail.com>
---
 syft/formats/common/cyclonedxhelpers/component.go     |  5 +++++
 .../formats/common/cyclonedxhelpers/component_test.go |  4 ++--
 syft/formats/common/property_encoder.go               |  2 +-
 syft/formats/syftjson/model/package.go                | 11 +++++++----
 syft/formats/syftjson/model/package_test.go           |  4 ++--
 syft/pkg/metadata.go                                  |  2 +-
 6 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/syft/formats/common/cyclonedxhelpers/component.go b/syft/formats/common/cyclonedxhelpers/component.go
index 0f2c1fd89b33..fb178307abcd 100644
--- a/syft/formats/common/cyclonedxhelpers/component.go
+++ b/syft/formats/common/cyclonedxhelpers/component.go
@@ -84,6 +84,11 @@ func decodeComponent(c *cyclonedx.Component) *pkg.Package {
 
 	p.Metadata = decodePackageMetadata(values, c, p.MetadataType)
 
+	// if there isn't a valid metadata struct, unset the type
+	if p.Metadata == nil {
+		p.MetadataType = pkg.NoMetadataType
+	}
+
 	if p.Type == "" {
 		p.Type = pkg.TypeFromPURL(p.PURL)
 	}
diff --git a/syft/formats/common/cyclonedxhelpers/component_test.go b/syft/formats/common/cyclonedxhelpers/component_test.go
index d1f7835ae3c2..f25151077b71 100644
--- a/syft/formats/common/cyclonedxhelpers/component_test.go
+++ b/syft/formats/common/cyclonedxhelpers/component_test.go
@@ -229,8 +229,8 @@ func Test_decodeComponent(t *testing.T) {
 					},
 				},
 			},
-			wantMetadataType: pkg.RpmMetadataType,
-			wantMetadata:     pkg.RpmMetadata{},
+			wantMetadataType: pkg.NoMetadataType,
+			wantMetadata:     nil,
 		},
 		{
 			name: "handle RpmdbMetadata type with properties",
diff --git a/syft/formats/common/property_encoder.go b/syft/formats/common/property_encoder.go
index e22772db0eb5..9db409425cd4 100644
--- a/syft/formats/common/property_encoder.go
+++ b/syft/formats/common/property_encoder.go
@@ -364,7 +364,7 @@ func decode(vals map[string]string, value reflect.Value, prefix string, fn Field
 
 func PtrToStruct(ptr interface{}) interface{} {
 	v := reflect.ValueOf(ptr)
-	if v.IsZero() && v.Type().Kind() != reflect.Struct {
+	if v.IsZero() {
 		return nil
 	}
 	switch v.Type().Kind() {
diff --git a/syft/formats/syftjson/model/package.go b/syft/formats/syftjson/model/package.go
index 4567a139aeb5..0993cbba142d 100644
--- a/syft/formats/syftjson/model/package.go
+++ b/syft/formats/syftjson/model/package.go
@@ -78,10 +78,13 @@ func unpackMetadata(p *Package, unpacker packageMetadataUnpacker) error {
 	typ, ok := pkg.MetadataTypeByName[p.MetadataType]
 	if ok {
 		val := reflect.New(typ).Interface()
-		if len(unpacker.Metadata) > 0 {
-			if err := json.Unmarshal(unpacker.Metadata, val); err != nil {
-				return err
-			}
+		if len(unpacker.Metadata) == 0 {
+			// if we don't have metadata, unset the metadata type
+			p.MetadataType = pkg.NoMetadataType
+			return nil
+		}
+		if err := json.Unmarshal(unpacker.Metadata, val); err != nil {
+			return err
 		}
 		p.Metadata = reflect.ValueOf(val).Elem().Interface()
 		return nil
diff --git a/syft/formats/syftjson/model/package_test.go b/syft/formats/syftjson/model/package_test.go
index 34677b20bf24..b54ab6bb5fee 100644
--- a/syft/formats/syftjson/model/package_test.go
+++ b/syft/formats/syftjson/model/package_test.go
@@ -217,8 +217,8 @@ func Test_unpackMetadata(t *testing.T) {
 			packageData: []byte(`{
 				"metadataType": "GolangBinMetadata"
 			}`),
-			metadataType: pkg.GolangBinMetadataType,
-			wantMetadata: pkg.GolangBinMetadata{},
+			metadataType: pkg.NoMetadataType,
+			wantMetadata: nil,
 		},
 		{
 			name: "can handle package with unknonwn metadata type and missing metadata",
diff --git a/syft/pkg/metadata.go b/syft/pkg/metadata.go
index c757c3f5ec66..e6d0f04c6b8d 100644
--- a/syft/pkg/metadata.go
+++ b/syft/pkg/metadata.go
@@ -9,7 +9,7 @@ type MetadataType string
 
 const (
 	// this is the full set of data shapes that can be represented within the pkg.Package.Metadata field
-
+	NoMetadataType               MetadataType = ""
 	UnknownMetadataType          MetadataType = "UnknownMetadata"
 	ApkMetadataType              MetadataType = "ApkMetadata"
 	AlpmMetadataType             MetadataType = "AlpmMetadata"