From 8f02f48acd6b2d9794833d8eb58a6e82764efcfb Mon Sep 17 00:00:00 2001
From: Scott Hanselman <scott@hanselman.com>
Date: Mon, 27 Apr 2026 23:20:20 -0700
Subject: [PATCH] fix(tui): dedupe ASCII backspace events

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 src/tui/tui.test.ts | 8 ++++++++
 src/tui/tui.ts      | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/tui/tui.test.ts b/src/tui/tui.test.ts
index 5a573090239..b9d41065472 100644
--- a/src/tui/tui.test.ts
+++ b/src/tui/tui.test.ts
@@ -210,6 +210,14 @@ describe("createBackspaceDeduper", () => {
     expect(dedupe("\x7f")).toBe("\x7f");
   });
 
+  it("treats ASCII BS as backspace when it is the first event", () => {
+    const { dedupe, advance } = createTimedDedupe();
+
+    expect(dedupe("\x08")).toBe("\x08");
+    advance(1);
+    expect(dedupe("\x7f")).toBe("");
+  });
+
   it("never suppresses non-backspace keys", () => {
     const dedupe = createBackspaceDeduper();
     expect(dedupe("a")).toBe("a");
diff --git a/src/tui/tui.ts b/src/tui/tui.ts
index a36a78bcd45..a382d3b0765 100644
--- a/src/tui/tui.ts
+++ b/src/tui/tui.ts
@@ -209,7 +209,7 @@ export function createBackspaceDeduper(params?: { dedupeWindowMs?: number; now?:
   let lastBackspaceAt = -1;
 
   return (data: string): string => {
-    if (!matchesKey(data, Key.backspace)) {
+    if (data !== "\x08" && !matchesKey(data, Key.backspace)) {
       return data;
     }
     const ts = now();