From 71b685aee0e7f2f7c7dbdbd3e9b91ece66a701a4 Mon Sep 17 00:00:00 2001
From: Brooklyn Nicholson <brooklyn.bb.nicholson@gmail.com>
Date: Thu, 30 Apr 2026 17:43:21 -0500
Subject: [PATCH] fix(tui): recover fragmented SGR mouse reports

---
 .../hermes-ink/src/ink/parse-keypress.test.ts |  32 ++++++
 .../hermes-ink/src/ink/parse-keypress.ts      | 103 +++++++++++++++---
 ui-tui/src/__tests__/terminalModes.test.ts    |  10 +-
 ui-tui/src/lib/terminalModes.ts               |   8 ++
 4 files changed, 136 insertions(+), 17 deletions(-)

diff --git a/ui-tui/packages/hermes-ink/src/ink/parse-keypress.test.ts b/ui-tui/packages/hermes-ink/src/ink/parse-keypress.test.ts
index 89c842c015..893eb42ed2 100644
--- a/ui-tui/packages/hermes-ink/src/ink/parse-keypress.test.ts
+++ b/ui-tui/packages/hermes-ink/src/ink/parse-keypress.test.ts
@@ -96,3 +96,35 @@ describe('mouse wheel modifier decoding', () => {
     expect(key).toMatchObject({ name: 'wheelup', meta: true })
   })
 })
+
+describe('fragmented SGR mouse recovery', () => {
+  it('re-synthesizes bracket-only SGR mouse tails as mouse events', () => {
+    const [[mouse]] = parseMultipleKeypresses(INITIAL_STATE, '[<35;159;11M')
+
+    expect(mouse).toMatchObject({ kind: 'mouse', button: 35, col: 159, row: 11, action: 'press' })
+  })
+
+  it('re-synthesizes angle-only SGR mouse tails as mouse events', () => {
+    const [[mouse]] = parseMultipleKeypresses(INITIAL_STATE, '<35;159;11M')
+
+    expect(mouse).toMatchObject({ kind: 'mouse', button: 35, col: 159, row: 11, action: 'press' })
+  })
+
+  it('re-synthesizes degraded SGR mouse bursts without leaking prompt text', () => {
+    const [events] = parseMultipleKeypresses(INITIAL_STATE, '5;142;11M<35;159;11M35;124;26M35;119;26Mtyped')
+
+    expect(events.slice(0, 4)).toEqual([
+      expect.objectContaining({ kind: 'mouse', button: 5, col: 142, row: 11 }),
+      expect.objectContaining({ kind: 'mouse', button: 35, col: 159, row: 11 }),
+      expect.objectContaining({ kind: 'mouse', button: 35, col: 124, row: 26 }),
+      expect.objectContaining({ kind: 'mouse', button: 35, col: 119, row: 26 })
+    ])
+    expect(events[4]).toMatchObject({ kind: 'key', sequence: 'typed' })
+  })
+
+  it('keeps isolated semicolon text that only resembles a prefixless mouse report', () => {
+    const [[key]] = parseMultipleKeypresses(INITIAL_STATE, 'see 1;2;3M for details')
+
+    expect(key).toMatchObject({ kind: 'key', sequence: 'see 1;2;3M for details' })
+  })
+})
diff --git a/ui-tui/packages/hermes-ink/src/ink/parse-keypress.ts b/ui-tui/packages/hermes-ink/src/ink/parse-keypress.ts
index 3a21aa2646..b79b839e85 100644
--- a/ui-tui/packages/hermes-ink/src/ink/parse-keypress.ts
+++ b/ui-tui/packages/hermes-ink/src/ink/parse-keypress.ts
@@ -63,6 +63,7 @@ const XTVERSION_RE = /^\x1bP>\|(.*?)(?:\x07|\x1b\\)$/s
 // Button 32=left-drag (0x20 | motion-bit). Plain 0/1/2 = left/mid/right click.
 // eslint-disable-next-line no-control-regex
 const SGR_MOUSE_RE = /^\x1b\[<(\d+);(\d+);(\d+)([Mm])$/
+const SGR_MOUSE_FRAGMENT_RE = /(?:\[<|<)?(?:[0-9]|[1-9][0-9]|1\d{2}|2[0-4]\d|25[0-5]);\d+;\d+[Mm]/g
 
 function createPasteKey(content: string): ParsedKey {
   return {
@@ -267,23 +268,22 @@ export function parseMultipleKeypresses(
     } else if (token.type === 'text') {
       if (inPaste) {
         pasteBuffer += token.value
-      } else if (/^\[<\d+;\d+;\d+[Mm]$/.test(token.value) || /^\[M[\x60-\x7f][\x20-\uffff]{2}$/.test(token.value)) {
-        // Orphaned SGR/X10 mouse tail (fullscreen only — mouse tracking is off
-        // otherwise). A heavy render blocked the event loop past App's 50ms
-        // flush timer, so the buffered ESC was flushed as a lone Escape and
-        // the continuation `[<btn;col;rowM` arrived as text. Re-synthesize
-        // with the ESC prefix so the scroll event still fires instead of
-        // leaking into the prompt. The spurious Escape is gone; App.tsx's
-        // readableLength check prevents it. The X10 Cb slot is narrowed to
-        // the wheel range [\x60-\x7f] (0x40|modifiers + 32) — a full [\x20-]
-        // range would match typed input like `[MAX]` batched into one read
-        // and silently drop it as a phantom click. Click/drag orphans leak
-        // as visible garbage instead; deletable garbage beats silent loss.
-        const resynthesized = '\x1b' + token.value
-        const mouse = parseMouseEvent(resynthesized)
-        keys.push(mouse ?? parseKeypress(resynthesized))
       } else {
-        keys.push(parseKeypress(token.value))
+        const mouseFragments = parseTextWithSgrMouseFragments(token.value)
+
+        if (mouseFragments) {
+          keys.push(...mouseFragments)
+        } else if (/^\[M[\x60-\x7f][\x20-\uffff]{2}$/.test(token.value)) {
+          // Orphaned X10 wheel tail (fullscreen only — mouse tracking is off
+          // otherwise). A heavy render blocked the event loop past App's 50ms
+          // flush timer, so the buffered ESC was flushed as a lone Escape and
+          // the continuation arrived as text. Re-synthesize with ESC so the
+          // scroll event still fires instead of leaking into the prompt.
+          const resynthesized = '\x1b' + token.value
+          keys.push(parseKeypress(resynthesized))
+        } else {
+          keys.push(parseKeypress(token.value))
+        }
       }
     }
   }
@@ -625,6 +625,77 @@ function parseMouseEvent(s: string): ParsedMouse | null {
   }
 }
 
+function normalizeSgrMouseFragment(fragment: string): string {
+  if (fragment.startsWith('[<')) {
+    return `\x1b${fragment}`
+  }
+
+  if (fragment.startsWith('<')) {
+    return `\x1b[${fragment}`
+  }
+
+  return `\x1b[<${fragment}`
+}
+
+function parseSgrMouseFragment(fragment: string): ParsedInput {
+  const sequence = normalizeSgrMouseFragment(fragment)
+  return parseMouseEvent(sequence) ?? parseKeypress(sequence)
+}
+
+function parseTextWithSgrMouseFragments(text: string): ParsedInput[] | null {
+  SGR_MOUSE_FRAGMENT_RE.lastIndex = 0
+
+  const matches = [...text.matchAll(SGR_MOUSE_FRAGMENT_RE)]
+  if (matches.length === 0) {
+    return null
+  }
+
+  const parsed: ParsedInput[] = []
+  let cursor = 0
+  let consumedAny = false
+
+  for (let i = 0; i < matches.length;) {
+    const first = matches[i]!
+    const run: RegExpMatchArray[] = [first]
+    let runEnd = first.index! + first[0].length
+    i++
+
+    while (i < matches.length && matches[i]!.index === runEnd) {
+      run.push(matches[i]!)
+      runEnd = matches[i]!.index! + matches[i]![0].length
+      i++
+    }
+
+    const hasExplicitMousePrefix = run.some(match => match[0].startsWith('[<') || match[0].startsWith('<'))
+    const isFragmentBurst = run.length > 1
+
+    if (!hasExplicitMousePrefix && !isFragmentBurst) {
+      continue
+    }
+
+    if (first.index! > cursor) {
+      parsed.push(parseKeypress(text.slice(cursor, first.index!)))
+    }
+
+    for (const match of run) {
+      parsed.push(parseSgrMouseFragment(match[0]))
+    }
+
+    cursor = runEnd
+    consumedAny = true
+  }
+
+  if (!consumedAny) {
+    return null
+  }
+
+  if (cursor < text.length) {
+    parsed.push(parseKeypress(text.slice(cursor)))
+  }
+
+  return parsed
+}
+
 function parseKeypress(s: string = ''): ParsedKey {
   let parts
 
diff --git a/ui-tui/src/__tests__/terminalModes.test.ts b/ui-tui/src/__tests__/terminalModes.test.ts
index 38ad8fe6a2..6b721b37f1 100644
--- a/ui-tui/src/__tests__/terminalModes.test.ts
+++ b/ui-tui/src/__tests__/terminalModes.test.ts
@@ -3,11 +3,19 @@ import { describe, expect, it, vi } from 'vitest'
 import { resetTerminalModes, TERMINAL_MODE_RESET } from '../lib/terminalModes.js'
 
 describe('terminal mode reset', () => {
-  it('includes the sticky input modes Hermes enables', () => {
+  it('includes common sticky input modes', () => {
+    expect(TERMINAL_MODE_RESET).toContain("\x1b[0'z")
+    expect(TERMINAL_MODE_RESET).toContain("\x1b[0'{")
+    expect(TERMINAL_MODE_RESET).toContain('\x1b[?2029l')
+    expect(TERMINAL_MODE_RESET).toContain('\x1b[?1016l')
+    expect(TERMINAL_MODE_RESET).toContain('\x1b[?1015l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?1006l')
+    expect(TERMINAL_MODE_RESET).toContain('\x1b[?1005l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?1003l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?1002l')
+    expect(TERMINAL_MODE_RESET).toContain('\x1b[?1001l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?1000l')
+    expect(TERMINAL_MODE_RESET).toContain('\x1b[?9l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?1004l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?2004l')
     expect(TERMINAL_MODE_RESET).toContain('\x1b[?1049l')
diff --git a/ui-tui/src/lib/terminalModes.ts b/ui-tui/src/lib/terminalModes.ts
index 7add599892..84d3f0850b 100644
--- a/ui-tui/src/lib/terminalModes.ts
+++ b/ui-tui/src/lib/terminalModes.ts
@@ -1,10 +1,18 @@
 import { writeSync } from 'node:fs'
 
 export const TERMINAL_MODE_RESET =
+  "\x1b[0'z" + // DEC locator reporting
+  "\x1b[0'{" + // selectable locator events
+  '\x1b[?2029l' + // passive mouse
+  '\x1b[?1016l' + // SGR-pixels mouse
+  '\x1b[?1015l' + // urxvt decimal mouse
   '\x1b[?1006l' + // SGR mouse
+  '\x1b[?1005l' + // UTF-8 extended mouse
   '\x1b[?1003l' + // any-motion mouse
   '\x1b[?1002l' + // button-motion mouse
+  '\x1b[?1001l' + // highlight mouse
   '\x1b[?1000l' + // click mouse
+  '\x1b[?9l' + // X10 mouse
   '\x1b[?1004l' + // focus events
   '\x1b[?2004l' + // bracketed paste
   '\x1b[?1049l' + // alternate screen