Keep SSH typing replies inside narrow split terminal panes (#24682)

tests/e2e/helpers/remote-typing-load-script.ts

@@ -15,7 +15,7 @@ export function remoteTypingLoadScript(runId: string): string {
     '  for (const char of chunk) {',
     "    if (char === '\\r' || char === '\\n') continue",
     '    seq += 1',
-    `    process.stdout.write('\\x1b[' + statusRow + ';2H\\x1b[2KREMOTE_KEY_${runId}_' + seq + '_' + char)`,
+    `    process.stdout.write('\\x1b[' + statusRow + ';2H\\x1b[2KKEY_${runId}_' + seq + '_' + char)`,
     '  }',
     '})'
   ].join(';')

tests/e2e/helpers/remote-typing-load-script.unit.test.ts

@@ -2,20 +2,31 @@ import '../../../src/main/daemon/xterm-env-polyfill'
 import { EventEmitter } from 'node:events'
 import { runInNewContext } from 'node:vm'
 import { Terminal } from '@xterm/headless'
+import { SerializeAddon } from '@xterm/addon-serialize'
 import { expect, it } from 'vitest'
 import { remoteTypingLoadScript } from './remote-typing-load-script'
 
-it.each([12, 24, 40])(
-  'keeps typed output visible through background pressure at %i rows',
-  async (rows) => {
-    const terminal = new Terminal({ rows, cols: 80, scrollback: 1000, allowProposedApi: true })
+it.each([
+  { rows: 12, cols: 80 },
+  { rows: 24, cols: 80 },
+  { rows: 40, cols: 80 },
+  { rows: 12, cols: 35 },
+  { rows: 24, cols: 35 },
+  { rows: 40, cols: 35 }
+])(
+  'keeps typed output visible through background pressure at $rows rows and $cols columns',
+  async ({ rows, cols }) => {
+    const terminal = new Terminal({ rows, cols, scrollback: 1000, allowProposedApi: true })
+    const serializer = new SerializeAddon()
+    terminal.loadAddon(serializer)
+    const runId = cols === 80 ? 'test' : '1790930671681_active'
     const input = new EventEmitter()
     const chunks: string[] = []
     let background = (): void => {
       throw new Error('Background pressure did not start')
     }
     try {
-      runInNewContext(remoteTypingLoadScript('test'), {
+      runInNewContext(remoteTypingLoadScript(runId), {
         process: {
           stdin: {
             isTTY: true,
@@ -24,7 +35,7 @@ it.each([12, 24, 40])(
             resume() {},
             on: input.on.bind(input)
           },
-          stdout: { rows, write: (chunk: string) => chunks.push(chunk) },
+          stdout: { rows, cols, write: (chunk: string) => chunks.push(chunk) },
           exit() {}
         },
         setTimeout: (callback: () => void) => callback(),
@@ -34,7 +45,7 @@ it.each([12, 24, 40])(
         },
         clearInterval() {}
       })
-      input.emit('data', 'ab\r\ncd')
+      input.emit('data', cols === 80 ? 'ab\r\ncd' : 'abcdefghij\r\n')
       for (let frame = 0; frame < 40; frame += 1) {
         background()
       }
@@ -48,7 +59,9 @@ it.each([12, 24, 40])(
             .getLine(terminal.buffer.active.baseY + row)
             ?.translateToString(true) ?? ''
       ).join('\n')
-      expect(screen).toContain('REMOTE_KEY_test_4_d')
+      const reply = cols === 80 ? 'KEY_test_4_d' : `KEY_${runId}_10_j`
+      expect(screen).toContain(reply)
+      expect(serializer.serialize()).toContain(reply)
     } finally {
       terminal.dispose()
     }

tests/e2e/ssh-docker-relay-perf.spec.ts

@@ -86,7 +86,7 @@ async function measureRemoteTyping(
   const latencies: number[] = []
   for (let index = 0; index < KEY_LATENCY_SAMPLES.length; index += 1) {
     const char = KEY_LATENCY_SAMPLES[index]
-    const marker = `REMOTE_KEY_${runId}_${index + 1}_${char}`
+    const marker = `KEY_${runId}_${index + 1}_${char}`
     const started = performance.now()
     await page.evaluate(({ ptyId, char }) => window.api.pty.write(ptyId, char, 'driving'), {
       ptyId,