Merge branch 'v0.18.x'

src/db/Selection.cxx

@@ -30,6 +30,18 @@ DatabaseSelection::DatabaseSelection(const char *_uri, bool _recursive,
 		uri = filter->GetBase();
 }
 
+bool
+DatabaseSelection::IsEmpty() const
+{
+	return uri.empty() && (filter == nullptr || filter->IsEmpty());
+}
+
+bool
+DatabaseSelection::HasOtherThanBase() const
+{
+	return filter != nullptr && filter->HasOtherThanBase();
+}
+
 bool
 DatabaseSelection::Match(const LightSong &song) const
 {

src/db/Selection.hxx

@@ -44,6 +44,15 @@ struct DatabaseSelection {
 	DatabaseSelection(const char *_uri, bool _recursive,
 			  const SongFilter *_filter=nullptr);
 
+	gcc_pure
+	bool IsEmpty() const;
+
+	/**
+	 * Does this selection contain constraints other than "base"?
+	 */
+	gcc_pure
+	bool HasOtherThanBase() const;
+
 	gcc_pure
 	bool Match(const LightSong &song) const;
 };

src/db/plugins/ProxyDatabasePlugin.cxx

@@ -695,6 +695,23 @@ SearchSongs(struct mpd_connection *connection,
 	return result && CheckError(connection, error);
 }
 
+/**
+ * Check whether we can use the "base" constraint.  Requires
+ * libmpdclient 2.9 and MPD 0.18.
+ */
+gcc_pure
+static bool
+ServerSupportsSearchBase(const struct mpd_connection *connection)
+{
+#if LIBMPDCLIENT_CHECK_VERSION(2,9,0)
+	return mpd_connection_cmp_server_version(connection, 0, 18, 0) >= 0;
+#else
+	(void)connection;
+
+	return false;
+#endif
+}
+
 bool
 ProxyDatabase::Visit(const DatabaseSelection &selection,
 		     VisitDirectory visit_directory,
@@ -706,7 +723,10 @@ ProxyDatabase::Visit(const DatabaseSelection &selection,
 	if (!const_cast<ProxyDatabase *>(this)->EnsureConnected(error))
 		return nullptr;
 
-	if (!visit_directory && !visit_playlist && selection.recursive)
+	if (!visit_directory && !visit_playlist && selection.recursive &&
+	    (ServerSupportsSearchBase(connection)
+	     ? !selection.IsEmpty()
+	     : selection.HasOtherThanBase()))
 		/* this optimized code path can only be used under
 		   certain conditions */
 		return ::SearchSongs(connection, selection, visit_song, error);