fix: add try/catch around getConsoleProcessList in conpty_console_list_agent

src/conpty_console_list_agent.test.ts

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) 2024, Microsoft Corporation (MIT License).
+ */
+
+import * as assert from 'assert';
+import * as path from 'path';
+import { fork } from 'child_process';
+
+if (process.platform === 'win32') {
+  describe('conpty_console_list_agent', () => {
+    it('should gracefully handle AttachConsole failure for a dead PID', (done) => {
+      const agentPath = path.join(__dirname, 'conpty_console_list_agent');
+      const deadPid = 999999;
+
+      const agent = fork(agentPath, [deadPid.toString()]);
+
+      agent.on('message', (message: { consoleProcessList: number[] }) => {
+        // When AttachConsole fails, the agent should fall back to returning
+        // just the shell PID rather than crashing.
+        assert.deepStrictEqual(message.consoleProcessList, [deadPid]);
+        done();
+      });
+
+      agent.on('exit', (code) => {
+        if (code !== 0) {
+          done(new Error(`Agent exited with code ${code}, expected graceful fallback`));
+        }
+      });
+    });
+  });
+}

src/conpty_console_list_agent.ts

@@ -10,6 +10,13 @@ import { loadNativeModule } from './utils';
 
 const getConsoleProcessList = loadNativeModule('conpty_console_list').module.getConsoleProcessList;
 const shellPid = parseInt(process.argv[2], 10);
-const consoleProcessList = getConsoleProcessList(shellPid);
-process.send!({ consoleProcessList });
+try {
+  const consoleProcessList = getConsoleProcessList(shellPid);
+  process.send!({ consoleProcessList });
+} catch {
+  // AttachConsole can fail if the shell process has already exited.
+  // Fall back to returning just the shell PID, matching the timeout
+  // fallback behavior in windowsPtyAgent.ts.
+  process.send!({ consoleProcessList: [shellPid] });
+}
 process.exit(0);