fix: review round 2 — Clear watch progress clears only the resume point, big view focus by the way it arrived, dialog name, reason tooltip, backfill locks

backend/tests/test_facebook_titles.py

@@ -6,9 +6,7 @@ no post text to fall back on, and the download name copied the placeholder too.
 the same reel (yt-dlp 2026.08.19, as on prod) still carries the post's text in its description.
 """
 
-import threading
-
-from sqlalchemy import update
+from sqlalchemy import select, update
 
 from app.config import settings
 from app.db import SessionLocal
@@ -149,8 +147,8 @@ def test_the_backfill_retitles_a_placeholder_download_and_the_names_that_repeate
 
 
 def test_a_name_given_while_the_backfill_runs_stays(db, make_user, monkeypatch):
-    # The owner renames the download between the backfill's retitle and its commit (the poster step
-    # sits between them): the owner's name wins, it is not overwritten by what was read before it.
+    # The owner renames the download while the backfill reads the page: the owner's name wins, it is
+    # not overwritten by what was read before it.
     _fake_ydl(monkeypatch, _PUBLIC)
     owner = make_user()
     asset = MediaAsset(
@@ -178,7 +176,9 @@ def test_a_name_given_while_the_backfill_runs_stays(db, make_user, monkeypatch):
     db.add(job)
     db.commit()
 
-    def rename():
+    read_page = backfill.public_title_info
+
+    def renamed_while_reading(*args):
         with SessionLocal() as other:
             other.execute(
                 update(DownloadJob)
@@ -186,27 +186,64 @@ def test_a_name_given_while_the_backfill_runs_stays(db, make_user, monkeypatch):
                 .values(display_name="Office jokes")
             )
             other.commit()
+        return read_page(*args)
 
-    def poster_while_renamed(a, root):
-        # A rename that must wait for the backfill's write waits here, and lands after its commit.
-        t = threading.Thread(target=rename)
-        t.start()
-        t.join(timeout=0.5)
-        renamers.append(t)
-        return None
-
-    renamers: list[threading.Thread] = []
-    monkeypatch.setattr(backfill.editmod, "ensure_poster", poster_while_renamed)
+    monkeypatch.setattr(backfill, "public_title_info", renamed_while_reading)
+    monkeypatch.setattr(backfill.editmod, "ensure_poster", lambda a, root: None)
 
     assert backfill.run()["retitled"] == 1
-    for t in renamers:
-        t.join(timeout=10)
-        assert not t.is_alive()
 
     db.expire_all()
     assert db.get(DownloadJob, job.id).display_name == "Office jokes"
 
 
+def test_the_poster_step_holds_no_row_lock(db, make_user, monkeypatch):
+    # It can cut a frame for 30 s. A delete locks the asset and then the job: with the job held here
+    # and the asset still to write, that is a deadlock, and a rename waits out the whole cut.
+    _fake_ydl(monkeypatch, _PUBLIC)
+    owner = make_user()
+    asset = MediaAsset(
+        source_kind="url",
+        source_ref=_URL,
+        format_sig="fb",
+        status="ready",
+        rel_path="facebook/x.mp4",
+        uploader_url="https://www.facebook.com/1",
+        title="Facebook",
+        ref_count=1,
+    )
+    db.add(asset)
+    db.flush()
+    job = DownloadJob(
+        user_id=owner.id,
+        asset_id=asset.id,
+        source_kind="url",
+        source_ref=_URL,
+        status="done",
+        queue_pos=0,
+        profile_snapshot={},
+        display_name="Facebook",
+    )
+    db.add(job)
+    db.commit()
+    asset_id, job_id = asset.id, job.id
+
+    def poster_finds_rows_free(a, root):
+        with SessionLocal() as other:
+            other.execute(
+                select(MediaAsset).where(MediaAsset.id == asset_id).with_for_update(nowait=True)
+            )
+            other.execute(
+                select(DownloadJob).where(DownloadJob.id == job_id).with_for_update(nowait=True)
+            )
+            other.rollback()
+        return None
+
+    monkeypatch.setattr(backfill.editmod, "ensure_poster", poster_finds_rows_free)
+
+    assert backfill.run()["retitled"] == 1
+
+
 def test_a_download_titled_facebook_is_named_from_the_signed_out_page(
     db, make_user, monkeypatch, tmp_path
 ):