From e7c1370075549f274bcff6dc26f3c58fc5b92169 Mon Sep 17 00:00:00 2001
From: Tarandeep Singh Juneja
 <tarandeepsinghjuneja@Tarandeeps-MacBook-Air.local>
Date: Fri, 3 Apr 2026 13:40:59 +0530
Subject: [PATCH] fix(terminal): prevent duplicate input on shell restart

Fixes #2 - When the agent shell restarted (e.g., after gitclaw exited),
user keystrokes were duplicated because onData handlers accumulated.
Typing 'hi' appeared as 'hhii'.

Changes:
- Register xterm.onData listener ONCE in constructor
- Store callback in dataHandler property
- onData() now replaces handler instead of stacking new ones
---
 src/terminal.ts | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/terminal.ts b/src/terminal.ts
index acdb859..b5571bc 100644
--- a/src/terminal.ts
+++ b/src/terminal.ts
@@ -5,6 +5,7 @@ export class TerminalManager {
   readonly xterm: Terminal;
   private readonly fitAddon: FitAddon;
   private resizeObserver: ResizeObserver | null = null;
+  private dataHandler: ((data: string) => void) | null = null;
 
   constructor() {
     this.xterm = new Terminal({
@@ -39,6 +40,11 @@ export class TerminalManager {
 
     this.fitAddon = new FitAddon();
     this.xterm.loadAddon(this.fitAddon);
+
+    // Register onData once in constructor to prevent duplicate handlers on restart
+    this.xterm.onData((data: string) => {
+      this.dataHandler?.(data);
+    });
   }
 
   /** Mount the terminal into a DOM element and start auto-resize. */
@@ -61,9 +67,11 @@ export class TerminalManager {
     this.xterm.write(data);
   }
 
-  /** Register a handler for user keystrokes (sent to shell stdin). */
+  /** Register a handler for user keystrokes (sent to shell stdin).
+   * Only one handler can be registered at a time; subsequent calls replace the previous handler.
+   */
   onData(handler: (data: string) => void): void {
-    this.xterm.onData(handler);
+    this.dataHandler = handler;
   }
 
   /** Current terminal dimensions for pty resize. */