From cb6773ea49dde61f7de6b4cf20a1f0dc601cd675 Mon Sep 17 00:00:00 2001
From: DaisyHunter <20070195+DaisyHunter@users.noreply.github.com>
Date: Fri, 25 Sep 2026 17:31:56 +0800
Subject: [PATCH] fix(fs): suppress visible console windows for git.exe
 children on Windows

UntrustedRepositoryGitCommand is the single channel for every git fact
aoci reads about a repository. When aoci itself runs console-less (MCP
stdio spawned by a host), Windows allocates a new visible console for
each git.exe child, so every refresh flashes a terminal window and
steals focus (issue #79).

hideChildConsole pins CREATE_NO_WINDOW + HideWindow on Windows and is a
no-op on other platforms. Stdio handle inheritance is untouched, so
host pipes and interactive terminal output behave exactly as before.

Evidence: console-less 'aoci check' sampled 1310 git.exe children with
zero windowed handles; on the patched binary gofmt/vet/staticcheck are
clean, the fs package tests (including a new invariant test) pass, and
linux/darwin/windows builds verify the platform stub. Blackbox suites
on Windows: conformance 44/46 (the 2 misses are the suite's own
aoci-code-relative expectations run against a third-party repo) and
scenarios 57 PASS / 2 CHARACTERIZED / 0 FAIL.

Fixes #79
---
 internal/fs/git_command.go              |  1 +
 internal/fs/git_command_other.go        |  8 +++++++
 internal/fs/git_command_windows.go      | 28 +++++++++++++++++++++++++
 internal/fs/git_command_windows_test.go | 25 ++++++++++++++++++++++
 4 files changed, 62 insertions(+)
 create mode 100644 internal/fs/git_command_other.go
 create mode 100644 internal/fs/git_command_windows.go
 create mode 100644 internal/fs/git_command_windows_test.go

diff --git a/internal/fs/git_command.go b/internal/fs/git_command.go
index 6a12411e..d45c595e 100644
--- a/internal/fs/git_command.go
+++ b/internal/fs/git_command.go
@@ -28,5 +28,6 @@ func UntrustedRepositoryGitCommand(root string, args ...string) *exec.Cmd {
 	}
 	command := exec.Command("git", append(hardened, args...)...)
 	command.Env = append(os.Environ(), "GIT_OPTIONAL_LOCKS=0")
+	hideChildConsole(command)
 	return command
 }
diff --git a/internal/fs/git_command_other.go b/internal/fs/git_command_other.go
new file mode 100644
index 00000000..20445697
--- /dev/null
+++ b/internal/fs/git_command_other.go
@@ -0,0 +1,8 @@
+//go:build !windows
+
+package fs
+
+import "os/exec"
+
+// hideChildConsole 在非 Windows 平台为空操作;可见控制台窗口问题仅 Windows 存在。
+func hideChildConsole(*exec.Cmd) {}
diff --git a/internal/fs/git_command_windows.go b/internal/fs/git_command_windows.go
new file mode 100644
index 00000000..eca20401
--- /dev/null
+++ b/internal/fs/git_command_windows.go
@@ -0,0 +1,28 @@
+//go:build windows
+
+// Windows 控制台抑制 —— 与 git_command.go 同包的平台侧实现
+//
+// 威胁: aoci 常以无控制台形态运行(如 MCP stdio 由宿主拉起)。此时 exec 拉起
+// 控制台子进程(git.exe)时,Windows 会为子进程新分配一个可见控制台窗口——
+// 刷新期间反复弹窗并抢占用户焦点。
+// 边界: CREATE_NO_WINDOW 只抑制控制台分配,不改变 stdio 句柄继承;宿主提供的
+// 管道与真实终端下的交互输出不受影响。HideWindow(STARTF_USESHOWWINDOW+SW_HIDE)
+// 作为兜底。调用方环境变量属操作者自身信任域,不在此处覆盖。
+package fs
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+// createNoWindow 即 Win32 CREATE_NO_WINDOW(0x08000000)。
+const createNoWindow = 0x08000000
+
+// hideChildConsole 阻止 Windows 为 git.exe 子进程新建可见控制台窗口。
+func hideChildConsole(cmd *exec.Cmd) {
+	if cmd.SysProcAttr == nil {
+		cmd.SysProcAttr = &syscall.SysProcAttr{}
+	}
+	cmd.SysProcAttr.HideWindow = true
+	cmd.SysProcAttr.CreationFlags |= createNoWindow
+}
diff --git a/internal/fs/git_command_windows_test.go b/internal/fs/git_command_windows_test.go
new file mode 100644
index 00000000..d8014d3c
--- /dev/null
+++ b/internal/fs/git_command_windows_test.go
@@ -0,0 +1,25 @@
+//go:build windows
+
+package fs
+
+import (
+	"testing"
+)
+
+// 无控制台父进程(如 MCP stdio 宿主)拉起 git.exe 时,Windows 会为子进程新分配
+// 可见控制台窗口。构造出的命令必须携带 CREATE_NO_WINDOW+HideWindow;本断言把
+// 窗口抑制固定为构造器不变量,防止后续重构静默丢失。
+func TestUntrustedRepositoryGitCommandSuppressesChildConsoleWindow(t *testing.T) {
+	command := UntrustedRepositoryGitCommand(t.TempDir(), "rev-parse", "--show-toplevel")
+	attr := command.SysProcAttr
+	if attr == nil {
+		t.Fatalf("git 调用必须设置 SysProcAttr 以抑制子进程控制台窗口")
+	}
+	if !attr.HideWindow {
+		t.Fatalf("git 调用必须设置 HideWindow")
+	}
+	if attr.CreationFlags&createNoWindow == 0 {
+		t.Fatalf("git 调用必须携带 CREATE_NO_WINDOW(0x%x),实际 CreationFlags=0x%x",
+			createNoWindow, attr.CreationFlags)
+	}
+}