Parse schemaVersion and descriptor fields in a single pass instead of
calling json.Unmarshal twice.
Signed-off-by: amarkdotdev <amarkdotdev@users.noreply.github.com>
Return a clear error when -f contains a manifest or index instead of an OCI
content descriptor, and reject descriptors missing a valid digest. Avoids
a nil-pointer panic when piping inspect --raw output into imagetools create.
Fixes#2091
Signed-off-by: amarkdotdev <amarkdotdev@users.noreply.github.com>
amarkdotdev