fix(images): key symlinked output folders and keep key work off the event loop (#332)

Review fixes: a source matches by its configured spelling too, so a
detected output folder that is a symlink keys its files (routes and
duplicate cleanup). File keys are computed in the executor. A path no
source holds is a plain 403, a lone surrogate a 400. The install repairs
a table that lacks its category index instead of refusing to open.

tests/test_api_image_categories.py

@@ -201,6 +201,27 @@ class TestSetAndClear(ImageCategoryTestCase):
             data = await self.delete(["a.png"], status=500)
         self.assertNotIn("secret", json.dumps(data))
 
+    async def test_a_symlinked_output_folder_keys_like_its_favorites(self):
+        """A detected output folder can be a symlink: keys use its real path."""
+        real = self.comfy_dir / "real-output"
+        make_png(real / "a.png")
+        link = self.comfy_dir / "linked-output"
+        self._make_symlink(real, link, target_is_directory=True)
+        self.api._get_all_output_dirs = lambda: [link]
+        data = await self.put(["a.png"], "Scans")
+        self.assertEqual(data["updated"], 1)
+        self.assertEqual(self.rows(), [(_favorite_root_key(link), "a.png", "Scans")])
+        self.assertEqual((await self.listed())["categories"], ["Scans"])
+        self.assertEqual((await self.delete(["a.png"]))["cleared"], 1)
+
+    async def test_lone_surrogates_are_400_not_500(self):
+        make_png(self.output_dir / "a.png")
+        await self.send(
+            "PUT", {"items": [self.target("a.png")], "category": "x\ud800"}, 400
+        )
+        await self.send("DELETE", {"items": [self.target("a\ud800.png")]}, 400)
+        self.assertEqual(self.rows(), [])
+
     async def test_delete_category_never_reaches_delete_image(self):
         make_png(self.output_dir / "a.png")
         calls = []

tests/test_duplicate_image_categories.py

@@ -134,3 +134,18 @@ class TestDuplicateCleanupKeepsCategories(DuplicateFilesTestCase):
         await asyncio.wait_for(asyncio.shield(cleanup.task), WAIT)
         self.assertFalse((self.output_dir / "sub" / "b.png").exists())
         self.assertEqual(self.api.db.image_category(sub_key, "a.png"), "Portraits")
+
+    async def test_a_symlinked_output_folder_still_moves_the_category(self):
+        link = self.output_dir.parent / "linked-output"
+        try:
+            os.symlink(self.output_dir, link, target_is_directory=True)
+        except (OSError, NotImplementedError):
+            self.skipTest("symlinks are not available")
+        self.trio()
+        with patch.object(self.api, "_get_all_output_dirs", return_value=[link]):
+            key = image_category_key([link], link / "b.png")
+            self.api.db.set_image_categories([key], "Portraits")
+            await self.run_cleanup()
+            kept = image_category_key([link], link / "a.png")
+        self.assertFalse((self.output_dir / "b.png").exists())
+        self.assertEqual(self.api.db.image_category(*kept), "Portraits")

tests/test_image_categories.py

@@ -195,7 +195,6 @@ class TestImageCategoriesSchema(_TempDir):
                 _INDEX_DDL,
             ),
             "wrong index": (_DDL, f"CREATE INDEX {INDEX} ON {TABLE}(updated_at)"),
-            "no index": (_DDL,),
             "extra index": (
                 _DDL,
                 _INDEX_DDL,
@@ -231,6 +230,17 @@ class TestImageCategoriesSchema(_TempDir):
                 )
                 with self.assertRaises(sqlite3.DatabaseError):
                     migrate_image_categories(conn)
+        # A table without its category index (never written by this code) is
+        # refused by the check but repaired by the install.
+        with closing(sqlite3.connect(":memory:")) as conn:
+            conn.execute(_DDL)
+            conn.execute(f"INSERT INTO {TABLE} VALUES ('r', 'a.png', 'Scans', 'now')")
+            self.assertIsNotNone(image_categories_schema_error(conn))
+            migrate_image_categories(conn)
+            self.assertIsNone(image_categories_schema_error(conn, allow_missing=False))
+            self.assertEqual(
+                conn.execute(f"SELECT COUNT(*) FROM {TABLE}").fetchone()[0], 1
+            )
         with closing(sqlite3.connect(":memory:")) as conn:
             migrate_image_categories(conn)
             migrate_image_categories(conn)  # idempotent