Support for empty search3 queries

We already did (at least with SQLite), make sure it's the case (ie: test it)
and prevent useless WHERE when querying the database

supysonic/api/search.py

@@ -200,9 +200,14 @@ def search_id3():
     song_offset = int(song_offset) if song_offset else 0
     root = get_root_folder(mfid)
 
-    artists = Artist.select().where(Artist.name.contains(query))
-    albums = Album.select().where(Album.name.contains(query))
-    songs = Track.select().where(Track.title.contains(query))
+    artists = Artist.select()
+    albums = Album.select()
+    songs = Track.select()
+
+    if query:
+        artists = artists.where(Artist.name.contains(query))
+        albums = albums.where(Album.name.contains(query))
+        songs = songs.where(Track.title.contains(query))
 
     if root is not None:
         artists = artists.join(Track).where(Track.root_folder == root)

tests/api/test_search.py

@@ -420,6 +420,12 @@ class SearchTestCase(ApiTestBase):
         )
         self.assertEqual(len(self._xpath(child, "./song")), 0)
 
+        # empty query
+        rv, child = self._make_request("search3", {"query": ""}, tag="searchResult3")
+        self.assertEqual(len(child), 27) # 3 + 3*2 + 3*2*3
+        self.assertEqual(len(self._xpath(child, "./artist")), 3)
+        self.assertEqual(len(self._xpath(child, "./album")), 6)
+        self.assertEqual(len(self._xpath(child, "./song")), 18)
 
 if __name__ == "__main__":
     unittest.main()