fix(cli): fix listener leak, silent failures, and error handling in early input capture

- Register cleanup for stdin listener in gemini.tsx to prevent orphaned
  listener on any error path before UI mounts
- Add try-catch and cancellation guard to setImmediate replay in
  KeypressContext to handle component unmount and replay errors gracefully
- Stop capture immediately and warn when buffer limit is reached instead
  of silently dropping data with a debug-level log
- Capture stdin reference at registration time so removeListener always
  operates on the correct stream instance
- Add debug log when early capture is skipped due to non-TTY stdin

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

Author: jinye.djy

packages/cli/src/gemini.tsx

@@ -58,7 +58,10 @@ import { getUserStartupWarnings } from './utils/userStartupWarnings.js';
 import { getCliVersion } from './utils/version.js';
 import { writeStderrLine } from './utils/stdioHelpers.js';
 import { computeWindowTitle } from './utils/windowTitle.js';
-import { startEarlyInputCapture } from './utils/earlyInputCapture.js';
+import {
+  startEarlyInputCapture,
+  stopAndGetCapturedInput,
+} from './utils/earlyInputCapture.js';
 import { validateNonInteractiveAuth } from './validateNonInterActiveAuth.js';
 import { showResumeSessionPicker } from './ui/components/StandaloneSessionPicker.js';
 import { initializeLlmOutputLanguage } from './utils/languageUtils.js';
@@ -385,6 +388,8 @@ export async function main() {
 
       // Startup optimization: start early input capture
       startEarlyInputCapture();
+      // Ensure the stdin listener is removed on any exit path (error, signal, etc.)
+      registerCleanup(() => stopAndGetCapturedInput());
 
       // This cleanup isn't strictly needed but may help in certain situations.
       process.on('SIGTERM', () => {

packages/cli/src/ui/contexts/KeypressContext.tsx

@@ -990,19 +990,29 @@ export function KeypressProvider({
     }
 
     // Startup optimization: replay captured input if available
+    let replayPending = false;
     if (capturedInput.length > 0) {
       debugLogger.debug(
         `Replaying ${capturedInput.length} bytes of captured input`,
       );
       // Process in next event loop tick to ensure subscribers are ready.
       // Always emit on stdin so that handleRawKeypress processes paste markers
       // correctly in passthrough mode.
+      // In non-passthrough mode, readline.emitKeypressEvents installs an internal
+      // 'data' listener on stdin that converts data events to keypress events.
+      replayPending = true;
       setImmediate(() => {
-        stdin.emit('data', capturedInput);
+        if (!replayPending) return;
+        try {
+          stdin.emit('data', capturedInput);
+        } catch (err) {
+          debugLogger.error('Failed to replay captured input:', err);
+        }
       });
     }
 
     return () => {
+      replayPending = false;
       if (usePassthrough) {
         keypressStream.removeListener('keypress', handleKeypress);
         stdin.removeListener('data', handleRawKeypress);

packages/cli/src/utils/earlyInputCapture.ts

@@ -38,6 +38,7 @@ let inputBuffer: InputBuffer = {
 };
 
 let captureHandler: ((data: Buffer) => void) | null = null;
+let captureStdin: NodeJS.ReadStream | null = null;
 let isCapturing = false;
 
 /**
@@ -191,6 +192,9 @@ function filterTerminalResponses(data: Buffer): Buffer {
  */
 export function startEarlyInputCapture(): void {
   if (isCapturing || !process.stdin.isTTY) {
+    if (!process.stdin.isTTY) {
+      debugLogger.debug('Early input capture skipped: stdin is not a TTY');
+    }
     return;
   }
 
@@ -216,7 +220,10 @@ export function startEarlyInputCapture(): void {
 
     // Check buffer size limit
     if (inputBuffer.totalBytes >= MAX_BUFFER_SIZE) {
-      debugLogger.debug('Buffer size limit reached, stopping capture');
+      debugLogger.warn(
+        `Early input capture buffer full (${MAX_BUFFER_SIZE} bytes). Stopping capture; additional keystrokes during startup will be lost.`,
+      );
+      stopEarlyInputCapture();
       return;
     }
 
@@ -243,19 +250,21 @@ export function startEarlyInputCapture(): void {
     }
   };
 
-  process.stdin.on('data', captureHandler);
+  captureStdin = process.stdin;
+  captureStdin.on('data', captureHandler);
 }
 
 /**
  * Stop early input capture
  * Call before KeypressProvider mounts
  */
 export function stopEarlyInputCapture(): void {
-  if (!isCapturing || !captureHandler) {
+  if (!isCapturing || !captureHandler || !captureStdin) {
     return;
   }
 
-  process.stdin.removeListener('data', captureHandler);
+  captureStdin.removeListener('data', captureHandler);
+  captureStdin = null;
   captureHandler = null;
   isCapturing = false;
   inputBuffer.captured = true;
@@ -300,10 +309,13 @@ export function hasCapturedInput(): boolean {
  * Reset capture state (for testing only)
  */
 export function resetCaptureState(): void {
-  if (captureHandler) {
+  if (captureHandler && captureStdin) {
+    captureStdin.removeListener('data', captureHandler);
+  } else if (captureHandler) {
     process.stdin.removeListener('data', captureHandler);
-    captureHandler = null;
   }
+  captureStdin = null;
+  captureHandler = null;
   isCapturing = false;
   inputBuffer = {
     chunks: [],