BRING BACK OLD LOGS

src/common/logging.cpp

@@ -247,6 +247,12 @@ struct ColorConsoleBackend final : public Backend {
 /// @brief Backend that writes to a file passed into the constructor
 struct FileBackend final : public Backend {
     explicit FileBackend(const std::filesystem::path& filename) noexcept {
+        auto old_filename = filename;
+        old_filename += ".old.txt";
+        // Existence checks are done within the functions themselves.
+        // We don't particularly care if these succeed or not.
+        void(FS::RemoveFile(old_filename));
+        void(FS::RenameFile(filename, old_filename));
         file.emplace(filename, FS::FileAccessMode::Write, FS::FileType::TextFile);
     }
     ~FileBackend() noexcept override = default;