[Bug] Composer input box disappears when deleting a markdown image reference in the draft

[wrj0001]

Bug report

Title: Composer input box disappears when deleting a markdown image reference in the draft

Summary

When the composer draft contains a markdown image reference whose URL starts with the relative path /describe-image/raw/... (the attachment route of the describe-image plugin), deleting that reference — either character by character or by selecting all and pressing Backspace — removes the entire composer input box from the page. The chat area itself stays, but the textarea/input bar is gone.

A second symptom of the same rendering path: any text that follows the image reference in the same paragraph is not rendered in the sent message (the text is still delivered to the model, only the UI drops it).

Environment

• DeepSeek Harness Web GUI (latest release), running at http://127.0.0.1:3080
• Windows 11, Edge / Chrome (reproduced in headless Chromium via Playwright too)
• Plugin involved: @linxin666/dsh-tool-describe-image (its attach route serves /describe-image/raw/<id>), but the crash is in the host composer's draft preview entry

Steps to reproduce

1. Open any conversation.
2. Click the composer input box.
3. Type (or paste): ![图片](/describe-image/raw/sha256:39be52c8fd3fb141d1c11b0bc9b20157c5baf4b938be2188cfcc767a66e47d86) asdasdasdasd
4. Press Ctrl+A then Backspace (or delete the reference character by character).
5. Observe: the whole composer bar disappears; document.querySelector('textarea') returns null.

Automated reproduction with Playwright:

await page.locator('textarea').first().fill(ref + ' asdasdasdasd');
await page.locator('textarea').first().press('Control+a');
await page.locator('textarea').first().press('Backspace');
// -> textarea count drops to 0

Console error

slot entry crashed in 'conversation.composer.bar': NotFoundError: Failed to execute 'removeChild' on 'Node': The node to be removed is not a child of this node.
    at B2 (http://127.0.0.1:3080/assets/index-Dqw48FrP.js:56:26239)
    at Pt (http://127.0.0.1:3080/assets/index-Dqw48FrP.js:56:27541)
    at Z2 (http://127.0.0.1:3080/assets/index-Dqw48FrP.js:56:28005)
    at Pt (http://127.0.0.1:3080/assets/index-Dqw48FrP.js:56:27691)
    at Z2 (http://127.0.0.1:3080/assets/index-Dqw48FrP.js:56:...)

Analysis / likely cause

The composer renders a preview entry for markdown image references found in the draft (slot conversation.composer.bar). When the reference text is deleted, React attempts removeChild on a node that was already removed by another update pass (double-removal race), the error escapes the slot entry, the slots system tears down the crashed entry, and the whole composer bar disappears.

The same preview entry also appears to swallow trailing text after the image in the rendered message.

Workaround used (for reference)

We worked around it by inserting a plain-text [image attachment {...}] note instead of a markdown image reference for pasted images; the note does not trigger the draft preview entry, so deletion is safe. A host-side fix would let plugins restore the nicer inline-image reference form.

Related

• Image rendering component in the host bundle only renders http(s) URLs (falls back to imageAlt text for other schemes), which may be worth revisiting together with this bug: /describe-image/raw/... relative paths render as alt text instead of the image in some surfaces.

[DRAG0NM]

已定位根因：composer 草稿中删除 markdown 图片引用（![…](…)）会触发 React commit 期 NotFoundError: removeChild（double-removal 竞态），随后整个输入框从页面消失（document.querySelector('textarea') 为 null），且不刷新页面无法恢复。 … 完整源码定位与修复方案见 #2210 。