mozilla-services/android-sync — comment on commit db2de0f8434be941663bbf5857bfbe7467200499
File: src/main/java/org/mozilla/gecko/sync/stage/SyncClientsEngineStage.java line 190
By marina-samuel:

My assumption is `if-unmodified-since` checks against the timestamp on the server of the last client record upload.

In the case where `if-unmodified-since` rejects the upload, we *do not* upload after processing commands because it means another client uploaded our record with commands so we need to process it first.

So if our local `serverClientRecordTimestamp` was updated when we last uploaded our client record, then uploading our record after processing our commands will fail if commands were uploaded by another client after our last upload.

Does that make sense or am I missing something?