Function: mediaIdentitiesMatch()

function mediaIdentitiesMatch(a: MediaDescriptor, b: MediaDescriptor): boolean;

Returns true iff two media descriptors describe the same physical media.

Strategy:

1. If both id fields are non-null and equal, they are the same.
2. Otherwise, fall back to dimension equality (widthMm and heightMm) — covers the common case of comparing a detected-from-printer descriptor (id may be absent) against a registry entry.

Apps use this for "is the loaded media the one I selected?" — what to do on mismatch (silent print, confirm, refuse) is the app's call. The contracts library does not enforce a policy.

Parameters

Parameter	Type
a	MediaDescriptor
b	MediaDescriptor

Returns

boolean