// metadataLayerEquivalent returns true if the last layer of a is equivalent to b, assuming
// that b is squashed over multiple layers, and a is not. b, for instance, will have an empty
// slice entrypoint, while a would have a nil entrypoint.
func metadataLayerEquivalent(a, b *docker.Config) bool {
if a.Entrypoint == nil && len(b.Entrypoint) == 0 {
// we are forced to set Entrypoint [] to reset the entrypoint
b.Entrypoint = nil
}
if len(a.OnBuild) == 1 && len(b.OnBuild) > 0 && a.OnBuild[0] == b.OnBuild[len(b.OnBuild)-1] {
// a layered file will only contain the last OnBuild statement
b.OnBuild = a.OnBuild
}
return metadataEqual(a, b)
}
