Update descriptor "data" field (when valid) during "crane edit config" (

#1584)

Signed-off-by: Tianon Gravi <admwiggin@gmail.com>

internal/cmd/edit.go

@@ -26,6 +26,7 @@ import (
 	"strings"
 
 	"github.com/google/go-containerregistry/internal/editor"
+	"github.com/google/go-containerregistry/internal/verify"
 	"github.com/google/go-containerregistry/pkg/crane"
 	"github.com/google/go-containerregistry/pkg/name"
 	v1 "github.com/google/go-containerregistry/pkg/v1"
@@ -188,6 +189,13 @@ func editConfig(in io.Reader, out io.Writer, src, dst string, options ...crane.O
 		edited = b
 	}
 
+	// this has to happen before we modify the descriptor (so we can use verify.Descriptor to validate whether m.Config.Data matches m.Config.Digest/Size)
+	if m.Config.Data != nil && verify.Descriptor(m.Config) == nil {
+		// https://github.com/google/go-containerregistry/issues/1552#issuecomment-1452653875
+		// "if data is non-empty and correct, we should update it"
+		m.Config.Data = edited
+	}
+
 	l := static.NewLayer(edited, m.Config.MediaType)
 	layerDigest, err := l.Digest()
 	if err != nil {