From a3487392c02af07b15e6da4806f88575a3b39e12 Mon Sep 17 00:00:00 2001
From: Muyue <muyue@legion-muyue.fr>
Date: Mon, 27 Apr 2026 14:39:26 +0200
Subject: [PATCH] fix(windows/conpty): pass HPCON value, not &hPC (v0.7.8)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

User reported regression introduced in v0.7.6: PowerShell / cmd open
in a separate external console window instead of attaching to the
xterm.js tab (v0.7.5 worked).

Root cause: the ConPTY wiring used
  attrList.Update(PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
                  unsafe.Pointer(&hPC),    // ← wrong
                  unsafe.Sizeof(hPC))

The PSEUDOCONSOLE attribute is a Win32 API quirk: lpValue must be
the HPCON *value* (cast to PVOID), not a pointer to the local
variable holding the handle. With &hPC the kernel reads garbage,
silently drops the attribute, and CreateProcessW spawns the child
with a fresh console — hence the external window.

Fix is one line:
  unsafe.Pointer(uintptr(hPC))

Confirmed against Microsoft's EchoCon sample and Go libraries that
work in production (UserExistsError/conpty, aymanbagabas/go-pty).

- internal/version/version.go: 0.7.7 → 0.7.8
- CHANGELOG.md: v0.7.8 entry with the diagnostic write-up
---
 CHANGELOG.md                            | 22 ++++++++++++++++++++++
 internal/api/terminal_conpty_windows.go |  8 +++++++-
 internal/version/version.go             |  2 +-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 74e4b69..b917b08 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,28 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## v0.7.8
+
+### Fix régression v0.7.6 : terminaux ouverts en fenêtre externe
+
+Symptôme rapporté : depuis v0.7.6, cliquer sur PowerShell / cmd dans l'onglet Terminal ouvre une **fenêtre console séparée** au lieu de s'afficher dans le tab xterm.js (régression — v0.7.5 fonctionnait).
+
+**Cause** : le binding ConPTY introduit en v0.7.6 passait `&hPC` (pointeur vers la variable Go locale) à `UpdateProcThreadAttribute(PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE, …)`. Or cet attribut est un quirk de l'API Win32 : `lpValue` doit être la **valeur du handle** (cast en `PVOID`), **pas** un pointeur vers la variable. Avec `&hPC`, le kernel lisait des octets aléatoires, l'attribut PSEUDOCONSOLE était silencieusement ignoré, et `CreateProcessW` créait une nouvelle console pour l'enfant — d'où la fenêtre externe.
+
+**Fix** (1 ligne) :
+
+```go
+// Avant
+unsafe.Pointer(&hPC)
+
+// Après
+unsafe.Pointer(uintptr(hPC))  // le HPCON value comme PVOID
+```
+
+Référence : Microsoft EchoCon sample + bibliothèques Go ConPTY existantes (`UserExistsError/conpty`, `aymanbagabas/go-pty`) utilisent toutes la valeur du handle directement.
+
+Conséquence : terminaux PowerShell / cmd / WSL s'ouvrent à nouveau **dans** le tab xterm.js avec TTY complet (ANSI, prompt couleur, vim, etc.).
+
 ## v0.7.7
 
 ### Fix : install Windows échoue silencieusement quand une version précédente tourne
diff --git a/internal/api/terminal_conpty_windows.go b/internal/api/terminal_conpty_windows.go
index 24aa9bb..92555a6 100644
--- a/internal/api/terminal_conpty_windows.go
+++ b/internal/api/terminal_conpty_windows.go
@@ -80,9 +80,15 @@ func startConptySession(cmd *exec.Cmd) (termSession, error) {
 		windows.CloseHandle(outRead)
 		return nil, fmt.Errorf("NewProcThreadAttributeList: %w", err)
 	}
+	// PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE is a quirk of the Win32 API: lpValue
+	// is the HPCON *value* (cast to PVOID), not a pointer to the handle. If
+	// we pass &hPC the kernel reads garbage, the PC attribute is silently
+	// ignored, and cmd/pwsh get their own external console window — which is
+	// exactly the regression v0.7.6 introduced. The cbSize stays the size of
+	// the handle (8 bytes on amd64). Reference: Microsoft EchoCon sample.
 	if err := attrList.Update(
 		procThreadAttributePseudoconsole,
-		unsafe.Pointer(&hPC),
+		unsafe.Pointer(uintptr(hPC)),
 		unsafe.Sizeof(hPC),
 	); err != nil {
 		attrList.Delete()
diff --git a/internal/version/version.go b/internal/version/version.go
index c475816..9b4dc74 100644
--- a/internal/version/version.go
+++ b/internal/version/version.go
@@ -7,7 +7,7 @@ import (
 
 const (
 	Name    = "muyue"
-	Version = "0.7.7"
+	Version = "0.7.8"
 	Author  = "La Légion de Muyue"
 )