exporter: avoid modifying exporter inputs

Co-authored-by: fahed dorgaa <fahed.dorgaa@gmail.com>
Co-authored-by: a-palchikov <deemok@gmail.com>
Signed-off-by: Justin Chadwell <me@jedevc.com>

exporter/containerimage/export.go

@@ -188,6 +188,7 @@ func (e *imageExporterInstance) Config() *exporter.Config {
 }
 
 func (e *imageExporterInstance) Export(ctx context.Context, src *exporter.Source, sessionID string) (_ map[string]string, descref exporter.DescriptorReference, err error) {
+	src = src.Clone()
 	if src.Metadata == nil {
 		src.Metadata = make(map[string][]byte)
 	}

exporter/oci/export.go

@@ -117,6 +117,7 @@ func (e *imageExporterInstance) Export(ctx context.Context, src *exporter.Source
 		return nil, nil, errors.Errorf("docker exporter does not currently support exporting manifest lists")
 	}
 
+	src = src.Clone()
 	if src.Metadata == nil {
 		src.Metadata = make(map[string][]byte)
 	}

solver/result/result.go

@@ -1,6 +1,7 @@
 package result
 
 import (
+	"maps"
 	"sync"
 
 	"github.com/pkg/errors"
@@ -14,6 +15,15 @@ type Result[T comparable] struct {
 	Attestations map[string][]Attestation[T]
 }
 
+func (r *Result[T]) Clone() *Result[T] {
+	return &Result[T]{
+		Ref:          r.Ref,
+		Refs:         maps.Clone(r.Refs),
+		Metadata:     maps.Clone(r.Metadata),
+		Attestations: maps.Clone(r.Attestations),
+	}
+}
+
 func (r *Result[T]) AddMeta(k string, v []byte) {
 	r.mu.Lock()
 	if r.Metadata == nil {