fix: every first watch state survives a write beside it, and a folded Watch later keeps its pin

A season marked watched, a pull from Plex and a YouTube resume point made their first row by a read
then an add, and failed on the unique key when a first checkpoint or the watched mark made it in
between. They go through the same insert-then-read as the checkpoint (the resume point is one
upsert); a pull that meets a local change still waiting for its push leaves it.

Folding duplicate Watch later lists moved their videos but not a Home pin, which the cascade then
deleted; the first pin of a dropped copy moves onto the kept list.

Marking one notice read trimmed before its own flag was flushed, so the trim left one past the cap.
The route test now crosses the cap and reads the result from a session of its own.

backend/alembic/versions/0112_one_watch_later.py

@@ -7,7 +7,9 @@ Create Date: 2026-10-20
 Watch later was made on a user's first save by a read then an insert, so two first saves at once
 each made a list, and the reader then picked between them at random. A partial unique index holds
 "one per user" now. An instance that already has a second list keeps the oldest: the others' videos
-move into it (after its own, in their order; one it already holds is not added twice), then they go.
+move into it (after its own, in their order; one it already holds is not added twice), a Home pin
+of one of them moves to it (unless it is pinned itself; of several, the first on the shelf), then
+they go — a pin left on them goes with them, as the kept list already holds one.
 """
 
 import sqlalchemy as sa
@@ -41,6 +43,19 @@ def upgrade() -> None:
         ON CONFLICT ON CONSTRAINT uq_playlist_video DO NOTHING
         """
     )
+    op.execute(
+        f"""
+        UPDATE comfort_pins c SET playlist_id = m.keep_id
+        FROM (
+            SELECT DISTINCT ON (e.keep_id) p.id AS pin_id, e.keep_id
+            FROM comfort_pins p
+            JOIN ({_EXTRA}) e ON e.id = p.playlist_id
+            WHERE NOT EXISTS (SELECT 1 FROM comfort_pins k WHERE k.playlist_id = e.keep_id)
+            ORDER BY e.keep_id, p.position, p.id
+        ) m
+        WHERE c.id = m.pin_id
+        """
+    )
     op.execute(f"DELETE FROM playlists WHERE id IN (SELECT id FROM ({_EXTRA}) e)")
     op.create_index(
         "uq_playlist_watch_later",

backend/app/notifications.py

@@ -49,7 +49,9 @@ def create_notification(
 
 def trim_read(db: Session, user_id: int, cap: int = READ_SOFT_CAP) -> int:
     """Delete a user's oldest READ notifications beyond `cap`. Returns the number removed.
-    Idempotent and cheap; safe to call after marking things read. Flushes; the caller commits."""
+    Idempotent and cheap; safe to call after marking things read. Flushes first, so a notice the
+    caller has just marked read counts; the caller commits."""
+    db.flush()
     ids = (
         db.execute(
             select(Notification.id)

backend/app/plex/service.py

@@ -302,16 +302,29 @@ def mark_finished(db: Session, user_id: int, item_id: int, now: datetime) -> boo
     return False
 
 
-def _state_row(db: Session, user: User, item_id: int, st: PlexState | None) -> PlexState:
+def state_row(
+    db: Session,
+    user: User | int,
+    item_id: int,
+    st: PlexState | None = None,
+    *,
+    synced: bool = False,
+) -> PlexState:
     """The user's state row on this item, made if the read before found none. Made by the insert
     itself (ON CONFLICT DO NOTHING) and then read: the first checkpoint of an item and the `final`
     flush beside it routinely both read "none", and a plain add let the second one fail on
-    `uq_plex_user_item` — a 500, and the push it was carrying lost."""
+    `uq_plex_user_item` — a 500, and the push it was carrying lost. Every first row goes through
+    here: a checkpoint, a status, a season marked at once, a pull from Plex. `synced` is what a row
+    made now says about Plex; a row another writer made first keeps its own."""
     if st is not None:
         return st
     db.execute(
         pg_insert(PlexState)
-        .values(user_id=user.id, item_id=item_id)
+        .values(
+            user_id=user if isinstance(user, int) else user.id,
+            item_id=item_id,
+            synced_to_plex=synced,
+        )
         .on_conflict_do_nothing(constraint="uq_plex_user_item")
     )
     made = queries.state(db, user, item_id)
@@ -342,7 +355,7 @@ def checkpoint(
 ) -> PlexState:
     """Record a resume position. `dirty` marks it not yet mirrored to Plex — set before a push, so
     the reconcile re-pushes it if the push fails and the push can settle it once Plex confirms."""
-    st = _state_row(db, user, item_id, st)
+    st = state_row(db, user, item_id, st)
     st.position_seconds = position
     st.progress_updated_at = now
     if dirty:
@@ -360,7 +373,7 @@ def set_status(
     db: Session, user: User, item_id: int, st: PlexState | None, status: str
 ) -> PlexState:
     """Set a watched or hidden status; watched also clears the resume point."""
-    st = _state_row(db, user, item_id, st)
+    st = state_row(db, user, item_id, st)
     st.status = status
     if status == "watched":
         st.watched_at = datetime.now(timezone.utc)
@@ -383,9 +396,8 @@ def bulk_state(
         st = existing.get(e.id)
         prev = st.status if st is not None else "new"
         if watched:
-            if st is None:
-                st = PlexState(user_id=user_id, item_id=e.id)
-                db.add(st)
+            st = state_row(db, user_id, e.id, st)
+            prev = st.status  # a first checkpoint beside this may have made it meanwhile
             st.status = "watched"
             st.watched_at = now
             st.position_seconds = 0

backend/app/plex/watch_sync.py

@@ -32,6 +32,8 @@ from app.db import SessionLocal
 from app.userscope import owned_by
 from app.plex.models import PlexItem, PlexLibrary, PlexLink, PlexState
 from app.plex.client import PlexClient, PlexError, PlexNotConfigured
+from app.plex import queries
+from app.plex.service import state_row
 from app.plex.sync import (
     _TYPE_EPISODE,
     _TYPE_MOVIE,
@@ -252,15 +254,7 @@ def push_state_to_plex(
         # Flag the row synced — but an "unwatched" via status=new deletes the row, so there may be
         # nothing to flag; that's fine (unscrobble still happened). Skip the flag if the row was
         # re-edited since we captured `expect_ts` (leave it dirty for its own push / the reconcile).
-        st = (
-            db.execute(
-                select(PlexState).where(
-                    owned_by(PlexState.user_id, user_id), PlexState.item_id == item_id
-                )
-            )
-            .scalars()
-            .first()
-        )
+        st = queries.state(db, user_id, item_id)
         if st is not None and _row_matches(st, expect_ts):
             st.synced_to_plex = True
             db.commit()
@@ -394,15 +388,7 @@ def _pull_apply(
     """Bring one Plex-side positive signal into Siftlode under last-write-wins. Returns
     "watched"/"in_progress" if it changed the row, else None. Never clears a row (un-watch is the
     full reconcile's job) — this only pulls in watched/resume."""
-    st = (
-        db.execute(
-            select(PlexState).where(
-                owned_by(PlexState.user_id, user_id), PlexState.item_id == item_id
-            )
-        )
-        .scalars()
-        .first()
-    )
+    st = queries.state(db, user_id, item_id)
     if _same_state(st, status, pos):
         if st is not None and not st.synced_to_plex:
             st.synced_to_plex = True  # already matches Plex → just settle the flag, no churn
@@ -423,8 +409,9 @@ def _pull_apply(
         # "almost always already pushed" assumption above excludes.
         return None
     if st is None:
-        st = PlexState(user_id=user_id, item_id=item_id)
-        db.add(st)
+        st = state_row(db, user_id, item_id, synced=True)
+        if not st.synced_to_plex:  # a local change made it first, beside this pull: the guard above
+            return None
     if status == "watched":
         st.status, st.position_seconds, st.watched_at, st.progress_updated_at = (
             "watched",

backend/app/reader/service.py

@@ -239,24 +239,33 @@ def clear_state(db: Session, user: User, video_id: str) -> None:
 
 def set_progress(db: Session, user: User, video_id: str, position: int) -> None:
     """The player's resume point. 0 clears it: a row holding nothing else goes, one with a status
-    (watched, hidden) keeps it with the position zeroed. The status itself is never changed here."""
-    row = queries.video_state(db, user, video_id)
+    (watched, hidden) keeps it with the position zeroed. The status itself is never changed here.
+    A position is one upsert on (user, video): the first checkpoint and the end-of-playback mark
+    beside it both read "no row", and a plain add let the second one fail on `uq_user_video`."""
     now = datetime.now(timezone.utc)
-    if not position:
-        if row is None:
-            return
-        if row.status == "new":
-            db.delete(row)
-        else:
-            row.position_seconds = 0
-            row.progress_updated_at = now
-        db.flush()
+    if position:
+        db.execute(
+            pg_insert(VideoState)
+            .values(
+                user_id=user.id,
+                video_id=video_id,
+                position_seconds=position,
+                progress_updated_at=now,
+            )
+            .on_conflict_do_update(
+                constraint="uq_user_video",
+                set_={"position_seconds": position, "progress_updated_at": now, "updated_at": now},
+            )
+        )
         return
+    row = queries.video_state(db, user, video_id)
     if row is None:
-        row = VideoState(user_id=user.id, video_id=video_id)
-        db.add(row)
-    row.position_seconds = position
-    row.progress_updated_at = now
+        return
+    if row.status == "new":
+        db.delete(row)
+    else:
+        row.position_seconds = 0
+        row.progress_updated_at = now
     db.flush()
 
 

backend/tests/test_migration_0112.py

@@ -1,8 +1,8 @@
 """Migration 0112's data step, DB-lane: a user who already has two Watch later lists keeps the oldest,
-with the other's videos moved in after its own (one it already held is not added twice), and the
-one-per-user index then refuses a second list.
+with the other's videos moved in after its own (one it already held is not added twice) and a Home
+pin of the other moved onto it, and the one-per-user index then refuses a second list.
 
-The schema half is checked by test_migrations.py; a video lost on the way is invisible there.
+The schema half is checked by test_migrations.py; a video or a pin lost on the way is invisible there.
 """
 
 from datetime import datetime, timezone
@@ -17,6 +17,25 @@ from app.catalog.models import Channel, Video
 from app.db import engine
 
 
+def _lists(conn, user_id: int, n: int) -> list[int]:
+    values = ", ".join(f"(:u, 'Watch later', 'watch_later', {i})" for i in range(n))
+    return list(
+        conn.execute(
+            text(
+                f"INSERT INTO playlists (user_id, name, kind, position) VALUES {values} RETURNING id"
+            ),
+            {"u": user_id},
+        ).scalars()
+    )
+
+
+def _pin(conn, user_id: int, playlist_id: int, position: int) -> None:
+    conn.execute(
+        text("INSERT INTO comfort_pins (user_id, playlist_id, position) VALUES (:u, :p, :pos)"),
+        {"u": user_id, "p": playlist_id, "pos": position},
+    )
+
+
 def test_a_second_watch_later_is_folded_into_the_first(db, make_user):
     user, other = make_user(), make_user()
     db.add(Channel(id="UCm", title="M"))
@@ -28,15 +47,8 @@ def test_a_second_watch_later_is_folded_into_the_first(db, make_user):
     command.downgrade(cfg, "0111_audit_request_id")
     try:
         with engine.begin() as conn:
-            ids = conn.execute(
-                text(
-                    "INSERT INTO playlists (user_id, name, kind, position) VALUES"
-                    " (:u, 'Watch later', 'watch_later', 0), (:u, 'Watch later', 'watch_later', 1),"
-                    " (:o, 'Watch later', 'watch_later', 0) RETURNING id"
-                ),
-                {"u": user.id, "o": other.id},
-            ).scalars()
-            first, second, theirs = list(ids)
+            first, second, third = _lists(conn, user.id, 3)
+            theirs, their_second = _lists(conn, other.id, 2)
             conn.execute(
                 text(
                     "INSERT INTO playlist_items (playlist_id, video_id, position) VALUES"
@@ -44,6 +56,12 @@ def test_a_second_watch_later_is_folded_into_the_first(db, make_user):
                 ),
                 {"a": first, "b": second, "c": theirs},
             )
+            # The user pinned two of the copies, the kept one neither: the first on the shelf moves.
+            _pin(conn, user.id, third, 0)
+            _pin(conn, user.id, second, 1)
+            # The other pinned both: the kept one's pin stays, and is the only one.
+            _pin(conn, other.id, their_second, 0)
+            _pin(conn, other.id, theirs, 1)
     finally:
         command.upgrade(cfg, "head")
 
@@ -58,6 +76,10 @@ def test_a_second_watch_later_is_folded_into_the_first(db, make_user):
             )
         ).all()
         assert [tuple(r) for r in items] == [(first, "v1", 0), (first, "v2", 1), (theirs, "v3", 0)]
+        pins = conn.execute(
+            text("SELECT user_id, playlist_id, position FROM comfort_pins ORDER BY user_id")
+        ).all()
+        assert [tuple(r) for r in pins] == [(user.id, first, 0), (other.id, theirs, 1)]
     with pytest.raises(IntegrityError), engine.begin() as conn:
         conn.execute(
             text(

backend/tests/test_plex_service.py

@@ -436,3 +436,17 @@ def test_a_first_write_that_lost_the_race_updates_the_winners_row(db, make_user)
     db.commit()
     rows = db.scalars(select(PlexState).where(PlexState.item_id == it.id)).all()
     assert [(r.position_seconds, r.status) for r in rows] == [(42, "hidden")]
+
+
+def test_a_season_marked_beside_a_first_checkpoint_updates_its_row(db, make_user, monkeypatch):
+    """Marking a season reads every episode's state once; a first checkpoint that made one row since
+    must be updated, not collided with on `uq_plex_user_item`."""
+    user = make_user()
+    lib = _lib(db)
+    ep = _movie(db, lib, "e-race")
+    _state(db, user, ep, position_seconds=10)  # the checkpoint that won, committed
+    monkeypatch.setattr(rollup, "item_state_map", lambda *a, **k: {})  # read before it committed
+    service.bulk_state(db, user.id, [ep], watched=True)
+    db.commit()
+    rows = db.scalars(select(PlexState).where(PlexState.item_id == ep.id)).all()
+    assert [(r.status, r.position_seconds) for r in rows] == [("watched", 0)]

backend/tests/test_plex_watch_sync.py

@@ -14,6 +14,7 @@ from types import SimpleNamespace
 from sqlalchemy import select
 
 from app.models import User
+from app.plex import queries
 from app.plex.models import PlexItem, PlexLibrary, PlexState
 from app.plex.watch_sync import _pull_apply, _reconcile_inprogress_movies
 from app.routes.plex.playback import (
@@ -385,3 +386,30 @@ def test_should_push_resume_periodic_is_throttled():
     )
     # Once the window elapses, the next tick pushes again.
     assert _should_push_resume(*key, now + timedelta(seconds=_PUSH_THROTTLE_S), final=False) is True
+
+
+def test_a_pull_that_lost_the_race_keeps_the_local_change_it_met(db, monkeypatch):
+    """The pull read "no state", and a first local checkpoint made one before it wrote: that row is
+    still waiting for its push, so the pull leaves it (the dirty guard), and fails on nothing."""
+    item_id, user_id = _seed_item_and_user(db)
+    now = datetime.now(timezone.utc)
+    db.add(PlexState(user_id=user_id, item_id=item_id, position_seconds=300, synced_to_plex=False))
+    db.commit()
+    real = queries.state
+    stale = [True]
+    monkeypatch.setattr(
+        queries, "state", lambda d, u, i: None if stale and stale.pop() else real(d, u, i)
+    )
+    assert _pull_apply(db, user_id, item_id, "new", 120, plex_ts=now) is None
+    db.commit()
+    rows = db.scalars(select(PlexState).where(PlexState.item_id == item_id)).all()
+    assert [(r.position_seconds, r.synced_to_plex) for r in rows] == [(300, False)]
+
+
+def test_a_first_pull_makes_a_row_in_step_with_plex(db):
+    item_id, user_id = _seed_item_and_user(db)
+    now = datetime.now(timezone.utc)
+    assert _pull_apply(db, user_id, item_id, "new", 120, plex_ts=now) == "in_progress"
+    db.commit()
+    rows = db.scalars(select(PlexState).where(PlexState.item_id == item_id)).all()
+    assert [(r.position_seconds, r.synced_to_plex) for r in rows] == [(120, True)]

backend/tests/test_reader_service.py

@@ -326,3 +326,18 @@ def test_a_watch_later_save_that_lost_the_race_uses_the_winners_list(db, make_us
     assert service.watch_later(db, user).id == won.id
     db.commit()
     assert [p.id for p in queries.playlists_for(db, user) if p.kind == "watch_later"] == [won.id]
+
+
+def test_a_first_resume_point_beside_the_watched_mark_lands_on_its_row(db, make_user, monkeypatch):
+    """The first checkpoint of a video and the end-of-playback mark both read "no row"; the
+    checkpoint that writes second must update the mark's row, not fail on `uq_user_video`."""
+    user = make_user()
+    _videos(db, "v1")
+    service.mark(db, user, "v1", "watched")  # the mark that won, committed
+    db.commit()
+    monkeypatch.setattr(queries, "video_state", lambda *a, **k: None)  # read before it committed
+    service.set_progress(db, user, "v1", 90)
+    db.commit()
+    db.expire_all()
+    rows = db.execute(select(VideoState)).scalars().all()
+    assert [(r.status, r.position_seconds) for r in rows] == [("watched", 90)]

backend/tests/test_route_commits.py

@@ -2,12 +2,14 @@
 
 A route's helper only flushes; the handler commits. The `db` fixture fails a test whose request left
 a write uncommitted, so every test here drives one successful write through its route and then
-reads the result back — a handler that lost its commit fails on both counts. The services' own
+reads the result back. The read-back holds that the handler called its unit; it runs in the
+request's own session, so it sees a write that was never committed — the commit is the fixture's
+to hold (a test that must see it committed reads from a session of its own). The services' own
 tests hold what each write does; these hold that the route finishes it. Nothing here reaches
 YouTube or Plex: the YouTube client is a stub and no user has a Plex link. Needs the DB.
 """
 
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone
 
 import pytest
 from sqlalchemy import select
@@ -17,7 +19,9 @@ from app.auth import require_write_scope
 from app.catalog.models import Channel, ExploredChannel, SearchFind, Subscription, Video
 from app.downloads.models import DownloadJob, DownloadProfile, DownloadShare
 from app.plex.models import PlexItem, PlexLibrary, PlexSeason, PlexShow, PlexState
+from app.db import SessionLocal
 from app.models import Notification
+from app.notifications import READ_SOFT_CAP
 from app.reader.models import SavedView, Tag, VideoState
 from app.routes import channels
 
@@ -343,14 +347,37 @@ def test_a_season_marked_watched_through_the_route_stays_watched(db, make_user,
     assert _plex_marks(db, user) == [("e1", "watched"), ("e2", "watched")]
 
 
-def test_reading_one_notice_is_committed_with_its_trim(db, make_user, as_user):
-    """Marking a notice read and trimming the read ones past the cap are one write the handler
-    commits — the trim no longer commits on its own."""
-    user = make_user()
-    n = Notification(user_id=user.id, type="t", title="x")
-    db.add(n)
+def _read_past_the_cap(db, user) -> list[Notification]:
+    """READ_SOFT_CAP read notices, oldest first, and one unread notice after them."""
+    base = datetime(2024, 1, 1, tzinfo=timezone.utc)
+    rows = [
+        Notification(
+            user_id=user.id,
+            type="t",
+            title=f"n{i}",
+            read=i < READ_SOFT_CAP,
+            created_at=base + timedelta(minutes=i),
+        )
+        for i in range(READ_SOFT_CAP + 1)
+    ]
+    db.add_all(rows)
     db.commit()
-    r = as_user(user).post(f"/api/me/notifications/{n.id}/read")
+    return rows
+
+
+def _committed_notices(user) -> tuple[int, bool]:
+    """What another session sees: how many of the user's notices are left, and whether the oldest is."""
+    with SessionLocal() as s:
+        ids = s.scalars(select(Notification.title).where(Notification.user_id == user.id)).all()
+    return len(ids), "n0" in ids
+
+
+@pytest.mark.parametrize("path", ["{id}/read", "read_all"])
+def test_reading_a_notice_past_the_cap_commits_the_trim(db, make_user, as_user, path):
+    """Marking a notice read makes READ_SOFT_CAP + 1 read ones: the handler commits the read flag and
+    the trim of the oldest together, and the trim counts the notice just read."""
+    user = make_user()
+    rows = _read_past_the_cap(db, user)
+    r = as_user(user).post("/api/me/notifications/" + path.format(id=rows[-1].id))
     assert r.json() == {"ok": True}
-    db.expire_all()
-    assert db.get(Notification, n.id).read is True
+    assert _committed_notices(user) == (READ_SOFT_CAP, False)