Follow-up to the cold review of 615e00a. The record was corrected to say only
that no NEW sentinel rows are created, but the test file's header still carried
the disclaimed "the data is clean at rest for every provider" claim — sitting on
the very test that supposedly proved it. It now states what the tests actually
pin, and names what they cannot speak to (rows written before this change, which
keep the sentinel and are covered only by the read coercion).
Also corrects docs/testing.md's ErsatzTV.Core.Tests count (543 -> ~650 measured;
the neighbouring Scanner.Tests cell is corrected in #602 instead, to keep the two
open PRs off the same line).
MediaSourceRepository's Plex/Jellyfin/Emby remove-and-recreate (disable-sync)
flows stamped SystemTime.MinValueUtc into library.LastScan, so normal use kept
minting 0001-01-01 sentinel rows. #409 fixed the READ side (the API coerces the
sentinel to null and a migration cleaned the historical residue), so the wire
contract was already correct — this stops new sentinel rows being written.
Safe because every remaining LastScan reader either coalesces
(LastScan ?? SystemTime.MinValueUtc) for its own non-nullable scan-comparison
needs, or is the API read-boundary coercion itself — audited every reference
under ErsatzTV{,.Application,.Core,.Infrastructure,.Scanner,.Mcp} plus web/.
There is no Where/OrderBy/GroupBy on LastScan anywhere, so the SQL
null-ordering divergence between SQLite and MySQL has no surface here.
Scan-comparison behavior is unchanged.
Deliberately ships NO second cleanup migration: rows written between #409's
NullOutNeverScannedLastScan and this change keep the sentinel at rest, and the
permanent read coercion — not a migration — is what keeps the contract honest
for them (as it must be anyway for a restored or hand-edited DB).
LibraryPath.LastScan is likewise left untouched: the flows re-add Paths with
their original values, and its only readers are the local-library scan
handlers, so it has no API surface and no remote-scan effect.
Regression test per provider (MediaSourceRepositoryDisableSyncTests), proven
non-vacuous: restoring the MinValue writes fails all three.
[decisions-edit] — the media.lastscan-null-boundary record documented this
write as an ONGOING sentinel source and rested its "the coercion is permanent"
argument on it, so the rationale prose is corrected in the same PR per
docs.decision-lifecycle. The Rule line is unchanged, so the generated
decisions/README.md catalog is byte-identical.
MediaSourceRepository.cs also loses its UTF-8 BOM (fix-as-you-touch, #311).
fixes#460
timothy