[Bug]: Dragging selected text into the desktop composer does nothing on macOS

[superheher]

Area

apps/web — macOS desktop

Steps to reproduce

1. Select text in another application, including a browser.
2. Drag the selection into the chat composer.
3. macOS shows the green insertion cursor, but releasing the mouse inserts nothing.

Expected behavior

The selected text is inserted at the drop position.

Actual behavior

The drop is silently ignored.

Environment

T3 Code Desktop, macOS

Version or commit

0.0.42 (719a76c)

[juliusmarminge]

Triage

Confirmed on stable v0.0.42 (719a76ca). No matching issue. The drop is cancelled in the composer, before the text is read. It is not an Electron navigation block, and it is not the workspace file-drop path (that one only claims drags whose types include Files, and it would show "Drop files to attach").

v0.0.42 mounts Lexical's PlainTextPlugin as the composer (ComposerPromptEditor.tsx). @lexical/plain-text@0.41.0 handles DROP_COMMAND like this:

// TODO: Make drag and drop work at some point.
event.preventDefault();
return true;

(packages/lexical-plain-text/src/index.ts at v0.41.0)

dragover is not cancelled, so Chromium still draws its drop caret (the green insertion cursor on macOS) at the pointer. drop is then cancelled whenever the editor has a range selection, which it does for a normal composer, including an empty one. The payload is never read, so the text is discarded. Paste is a different command and still inserts.

The same composer is what the desktop app embeds, so this is not specific to the Electron shell. Any v0.0.42 client using that editor does it.

This is already fixed on main. #12160 replaced that Lexical editor with Tiptap. ProseMirror's drop handler inserts text/plain (or text/html when that is what the drag carries) at the pointer. The first nightly that contains it is v0.0.43-nightly.20260917.1851. No stable tag after v0.0.42 has been published.

On the desktop app: Settings → General → Update track → Nightly, then check for updates. Switching the track back to Stable later stays on whatever build you have until the next stable.

[juliusmarminge]

Thanks for taking the time to report this and provide the details. We revisited it during the orchestrator V2 cleanup.

The reported v0.0.42 text-drop cancellation was owned by the removed Lexical PlainTextPlugin. The current composer uses Tiptap/ProseMirror and does not install that DROP_COMMAND cancellation. This specifically retires the old composer failure, consistent with the latest source diagnosis.

I’m closing this report because the implementation it targets has been replaced. That does not mean every similar symptom is fixed.

Source reviewed.

No macOS drag test was run. A fresh failure with the current Tiptap composer would need a new reproduction.

If you still hit this on a current build, please reply with the app/server versions and the steps that reproduce it. We can reopen this if the original problem is still there.