Crash on Windows when trying to save file if a nearby filename contains an emoji

[nixxquality]

Environment

• Elixir & Erlang/OTP versions (elixir --version): Erlang/OTP 26, Elixir 1.16.2
• Operating system: Windows 10
• How have you started Livebook (mix phx.server, livebook CLI, Docker, etc): Happens with both released Windows exe and mix phx.server
• Livebook version (use git rev-parse HEAD if running with mix): cb11b26
• Browsers that reproduce this bug (the more the merrier): All
• Include what is logged in the browser console:

[error] GenServer #PID<0.1393.0> terminating
** (UnicodeConversionError) invalid code point 55357
    (elixir 1.16.2) lib/list.ex:1103: List.to_string/1
    (elixir 1.16.2) lib/enum.ex:1700: Enum."-map/2-lists^map/1-1-"/2
    (elixir 1.16.2) lib/enum.ex:1700: Enum."-map/2-lists^map/1-1-"/2
    (elixir 1.16.2) lib/file.ex:1670: File.ls/1
    (livebook 0.13.0-dev) lib/livebook/file_system/local.ex:50: Livebook.FileSystem.Livebook.FileSystem.Local.list/3
    (livebook 0.13.0-dev) lib/livebook/file_system/file.ex:167: Livebook.FileSystem.File.list/2
    (livebook 0.13.0-dev) lib/livebook_web/live/file_select_component.ex:664: LivebookWeb.FileSelectComponent.get_file_infos/3
    (livebook 0.13.0-dev) lib/livebook_web/live/file_select_component.ex:617: LivebookWeb.FileSelectComponent.update_file_infos/2
    (livebook 0.13.0-dev) lib/livebook_web/live/file_select_component.ex:74: LivebookWeb.FileSelectComponent.update/2
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/utils.ex:498: Phoenix.LiveView.Utils.maybe_call_update!/3
    (elixir 1.16.2) lib/enum.ex:1700: Enum."-map/2-lists^map/1-1-"/2
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/diff.ex:685: anonymous fn/4 in Phoenix.LiveView.Diff.render_pending_components/6
    (telemetry 1.2.1) c:/Users/Linus/Code/livebook/deps/telemetry/src/telemetry.erl:321: :telemetry.span/3
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/diff.ex:680: anonymous fn/4 in Phoenix.LiveView.Diff.render_pending_components/6
    (stdlib 5.0) maps.erl:416: :maps.fold_1/4
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/diff.ex:639: Phoenix.LiveView.Diff.render_pending_components/6
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/diff.ex:143: Phoenix.LiveView.Diff.render/3
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/static.ex:249: Phoenix.LiveView.Static.to_rendered_content_tag/4
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/static.ex:132: Phoenix.LiveView.Static.render/3
    (phoenix_live_view 0.20.6) lib/phoenix_live_view/controller.ex:39: Phoenix.LiveView.Controller.live_render/3
Last message: {:continue, :handle_connection}
State: {%ThousandIsland.Socket{socket: #Port<0.25>, transport_module: ThousandIsland.Transports.TCP, read_timeout: 60000, silent_terminate_on_error: false, span: %ThousandIsland.Telemetry{span_name: :connection, telemetry_span_context: #Reference<0.546146728.560463878.35862>, start_time: 3970266607, start_metadata: %{remote_port: 58260, remote_address: {127, 0, 0, 1}, telemetry_span_context: #Reference<0.546146728.560463878.35862>, parent_telemetry_span_context: #Reference<0.546146728.560463878.32837>}}}, %{opts: %{websocket: [], http_1: [max_header_length: 32768], http_2: [max_header_value_length: 32768]}, plug: {Phoenix.Endpoint.SyncCodeReloadPlug, {LivebookWeb.Endpoint, []}}, handler_module: Bandit.InitialHandler, http_1_enabled: true, http_2_enabled: true, websocket_enabled: true}}

Current behavior

On Windows, if you have a file with an emoji in the filename in your home folder, the application crashes when trying to save your livebook.
Note: This is strictly an upstream issue. See elixir-lang/elixir#10959 and erlang/otp#4779.
The issue is known, but seems to be stalled upstream. I don't know if you want to make a workaround for this or not.

Workaround

Rename or move any files containing emoji in their filenames away from your home directory, or any directories you traverse with the file browser.

[Jonatan Kłosko]

An alternative workaround would be to paste a path directly instead of navigating through the problematic directories.

We could catch the error and return [] from ls, that wouldn't exactly fix the navigation (there would be no entries to click), it would just avoid the crash while typing. Given how rare emoji filenames are, I would just wait for the fix in OTP. @josevalim whichever you prefer!

[José Valim]

@jonatanklosko we can use this instead:

# Erlang currently chokes on emoji directories on Windows,
# so we discard those.
case :file.list_dir(dir) do
  {:ok, list} ->
    {:ok, for(dir <- list, str = try do IO.chardata_to_string(dir) rescue _ -> nil end, do: str )}
  {:error, error} ->
    {:error, error}
end

So we keep it working on all cases?

[Jonatan Kłosko]

@josevalim ah we can filter individual names, sounds good! #2558