From 79554198ec8aed107653f82e2d67ca5cb6ff5705 Mon Sep 17 00:00:00 2001
From: xxiaoxiong <2482929840@qq.com>
Date: Thu, 28 May 2026 22:07:18 +0800
Subject: [PATCH] fix: clear stale mention state when @ button insertion is
 invalid

When the @ button is clicked at a position where the regex does not
match (e.g., immediately after a word or on a second click after the
button just inserted @), the handler now explicitly clears any existing
mention state instead of leaving it intact.

This prevents the popover from remaining bound to a previous cursor
position, which would cause picking a file to replace the old mention
location and leave the newly inserted @ behind.

Mirrors the handleChange behavior which already clears mention when
the regex stops matching.
---
 apps/web/src/components/ChatComposer.tsx | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/apps/web/src/components/ChatComposer.tsx b/apps/web/src/components/ChatComposer.tsx
index 2ab6de779..5cfc96702 100644
--- a/apps/web/src/components/ChatComposer.tsx
+++ b/apps/web/src/components/ChatComposer.tsx
@@ -774,8 +774,12 @@ export const ChatComposer = forwardRef<ChatComposerHandle, Props>(
                   // does when it detects a fresh @ in the typed input.
                   const pos = cursor + 1;
                   const textBefore = next.slice(0, pos);
-                  const m = /(^|\s)@([^\s@]*)$/.exec(textBefore);
-                  if (m) setMention({ q: m[2] ?? '', cursor: pos });
+                  const m = /(^|\\s)@([^\\s@]*)$/.exec(textBefore);
+                  if (m) {
+                    setMention({ q: m[2] ?? '', cursor: pos });
+                  } else {
+                    setMention(null);
+                  }
                   requestAnimationFrame(() => {
                     ta.focus();
                     ta.setSelectionRange(pos, pos);