fix: new instance must not reuse the old _MEI unpack dir (1.2.7)

The update script is spawned from inside the frozen app, so the child
inherits _PYI_APPLICATION_HOME_DIR / _PYI_ARCHIVE_FILE. Combined with
MEI dir names being derived from the pid, a new instance could end up
loading python313.dll from the directory the old process was deleting,
giving 'Failed to load Python DLL ... module not found'.

- strip _PYI_* and PYINSTALLER_* from the environment of every child
- run the new instance with its own TEMP under updates/runtime
- wait for the old processes to actually exit before swapping files
- retry the launch and verify the process is still alive
- replace Get-FileHash / Get-ChildItem -Directory with PS 2.0 safe code

src/updater.py

@@ -125,6 +125,22 @@ def powershell_exe():
     return path if os.path.exists(path) else "powershell.exe"
 
 
+def clean_env():
+    """去掉 PyInstaller 的 _PYI_* / PYINSTALLER_* 变量后再启动子进程。
+
+    单文件程序解压到 %TEMP%\\_MEIxxxxxx，并通过 _PYI_APPLICATION_HOME_DIR
+    把这个路径告诉子进程。更新脚本本身是从播放器内部启动的，会一路继承到
+    新拉起的 exe 上，导致新实例复用旧解压目录；而旧进程退出时正在删除该
+    目录，于是出现 "Failed to load Python DLL ... 找不到指定的模块"。
+    """
+    env = os.environ.copy()
+    for key in list(env):
+        upper = str(key).upper()
+        if upper.startswith("_PYI") or upper.startswith("PYINSTALLER_"):
+            env.pop(key, None)
+    return env
+
+
 def build_install_script(current, downloaded, pid, digest="", parent_pid=None):
     """生成 Unicode 安全的更新脚本：校验副本后再交换文件，任何失败路径都会重新拉起程序。"""
     current = os.path.abspath(current)
@@ -148,20 +164,65 @@ function Write-UpdateLog($message) {
         Add-Content -LiteralPath $log -Encoding UTF8 -Value ("[" + (Get-Date -Format 'yyyy-MM-dd HH:mm:ss') + "] " + $message)
     } catch {}
 }
+# 新实例必须自己解压，不能复用本进程（以及旧播放器）的 _MEI 目录。
+# 而且 _MEI 目录名是按 pid 编码的，旧进程延迟清理时可能撞掉新进程刚建好的
+# 同名目录（pid 复用），于是出现 "Failed to load Python DLL"。把新实例的运行
+# 临时目录挪到我们自己的目录下，彻底避开这种竞争。
+$runtime = Join-Path (Split-Path -Parent $logDir) "runtime"
+function Prepare-Runtime {
+    try {
+        New-Item -ItemType Directory -Force -Path $runtime | Out-Null
+        # 不用 Get-ChildItem -Directory，兼容 Windows 7 自带的 PowerShell 2.0
+        Get-ChildItem -LiteralPath $runtime -Force -ErrorAction SilentlyContinue |
+            Where-Object { $_.PSIsContainer -and $_.Name -like "_MEI*" } |
+            Remove-Item -Recurse -Force -ErrorAction SilentlyContinue
+        $env:TEMP = $runtime
+        $env:TMP = $runtime
+        Write-UpdateLog ("runtime temp -> " + $runtime)
+    } catch {
+        Write-UpdateLog ("runtime temp failed: " + $_.Exception.Message)
+    }
+}
+function Get-Sha256($path) {
+    $stream = [System.IO.File]::Open($path, 'Open', 'Read', 'Read')
+    try {
+        $sha = New-Object System.Security.Cryptography.SHA256Managed
+        $bytes = $sha.ComputeHash($stream)
+        $sb = New-Object System.Text.StringBuilder
+        foreach ($b in $bytes) { [void]$sb.Append($b.ToString('x2')) }
+        return $sb.ToString()
+    } finally {
+        $stream.Close()
+    }
+}
+function Clear-FrozenEnv {
+    foreach ($name in @('_PYI_APPLICATION_HOME_DIR','_PYI_ARCHIVE_FILE','_PYI_PARENT_PROCESS_LEVEL','_PYI_SPLASH_IPC','PYINSTALLER_RESET_ENVIRONMENT','PYINSTALLER_STRICT_UNPACK_MODE','PYINSTALLER_SUPPRESS_SPLASH_SCREEN')) {
+        Remove-Item -Path ("Env:\" + $name) -Force -ErrorAction SilentlyContinue
+    }
+}
 function Start-App($path) {
     if (-not $path) { return $false }
     if (-not (Test-Path -LiteralPath $path)) {
         Write-UpdateLog ("missing target: " + $path)
         return $false
     }
-    try {
-        Start-Process -FilePath $path -WorkingDirectory (Split-Path -Parent $path) -ErrorAction Stop
-        Write-UpdateLog ("started: " + $path)
-        return $true
-    } catch {
-        Write-UpdateLog ("start failed: " + $path + " :: " + $_.Exception.Message)
-        return $false
+    Clear-FrozenEnv
+    Prepare-Runtime
+    for ($attempt = 1; $attempt -le 3; $attempt++) {
+        try {
+            $proc = Start-Process -FilePath $path -WorkingDirectory (Split-Path -Parent $path) -PassThru -ErrorAction Stop
+            Start-Sleep -Milliseconds 2000
+            if (-not $proc.HasExited) {
+                Write-UpdateLog ("started: " + $path + " (pid=" + $proc.Id + ")")
+                return $true
+            }
+            Write-UpdateLog ("process exited at once, attempt " + $attempt)
+        } catch {
+            Write-UpdateLog ("start failed: " + $path + " :: " + $_.Exception.Message)
+        }
+        Start-Sleep -Milliseconds 1500
     }
+    return $false
 }
 
 Write-UpdateLog "=== update begin; pids=__PIDS_TEXT__ ==="
@@ -171,7 +232,19 @@ Start-Sleep -Seconds 2
 foreach ($p in @(__PIDS__)) {
     try { Stop-Process -Id $p -Force -ErrorAction SilentlyContinue } catch {}
 }
-Start-Sleep -Milliseconds 1200
+$gone = $false
+$waited = 0
+for ($i = 0; $i -lt 80; $i++) {
+    $alive = 0
+    foreach ($p in @(__PIDS__)) {
+        if (Get-Process -Id $p -ErrorAction SilentlyContinue) { $alive++ }
+    }
+    if ($alive -eq 0) { $gone = $true; break }
+    Start-Sleep -Milliseconds 250
+    $waited += 250
+}
+Write-UpdateLog ("old processes stopped=" + $gone + " after " + $waited + " ms")
+Start-Sleep -Milliseconds 1500
 
 $staged = $dst + ".update"
 $backup = $dst + ".bak"
@@ -182,8 +255,9 @@ for ($i = 0; $i -lt 30; $i++) {
     try {
         Copy-Item -LiteralPath $src -Destination $staged -Force -ErrorAction Stop
         if ($expected) {
-            $actual = (Get-FileHash -LiteralPath $staged -Algorithm SHA256).Hash
-            if ($actual -ne $expected) { throw "SHA256 mismatch" }
+            # 用 .NET 而不是 Get-FileHash，兼容没有 PowerShell 4.0 的老系统
+            $actual = Get-Sha256 $staged
+            if ($actual -ne $expected.ToLower()) { throw "SHA256 mismatch" }
         }
         $verified = $true
         Write-UpdateLog "staged copy verified"
@@ -548,6 +622,7 @@ class UpdateDialog(QDialog):
                 ],
                 creationflags=CREATE_NO_WINDOW,
                 close_fds=True,
+                env=clean_env(),
                 stdin=subprocess.DEVNULL,
                 stdout=subprocess.DEVNULL,
                 stderr=subprocess.DEVNULL,
@@ -576,6 +651,7 @@ class UpdateDialog(QDialog):
                 cwd=os.path.dirname(path),
                 creationflags=CREATE_NO_WINDOW,
                 close_fds=True,
+                env=clean_env(),
                 stdin=subprocess.DEVNULL,
                 stdout=subprocess.DEVNULL,
                 stderr=subprocess.DEVNULL,

src/version.py

@@ -2,6 +2,6 @@
 
 APP_NAME = "网易云播放器"
 APP_VERSION = "1.2.7"
-BUILD_DATE = "2026-10-31"
+BUILD_DATE = "2026-11-01"
 UPDATE_ENDPOINT = "https://music.yuncishu.xyz/api/app/update"
 DOWNLOAD_PAGE = "https://music.yuncishu.xyz/download/"