dsh help me find some bugs about itself

[yanglaofish]

Upstream issue draft: dsh-win32-process — Win32 child env block keeps case-duplicate keys (no_proxy + NO_PROXY)

用途：粘贴到 https://github.com/deepseek-ai/deepseek-harness/issues
中文摘要见文末。

Title

Windows: spawned child environment block contains case-duplicate entries (no_proxy and NO_PROXY), breaking PowerShell Env: / Start-Process ("duplicate key" ArgumentException)

Summary

On Windows, every subprocess spawned by the harness receives an environment block that contains both the lowercase and uppercase spellings of proxy variables (no_proxy/NO_PROXY, http_proxy/HTTP_PROXY, https_proxy/HTTPS_PROXY). The duplicate entries are produced by dsh-win32-process's custom CreateProcessW path (encodeWindowsEnvironment), which sorts case-insensitively but does not de-duplicate folded keys. Node's own libuv child_process path collapses these (verified empirically), which is why the defect only shows on the custom Windows spawner.

Contrary to appearing like "stale residue" from a removed proxy plugin, the duplicates are re-generated on every spawn: dsh-subprocess imports proxyEnvironmentForChild() from dsh-http-proxy and overlays both casings into every child environment (NODE_USE_ENV_PROXY=1 is injected by that same function and appears in every spawned child, proving per-spawn injection).

Environment

• DSH Desktop (dsh-plugin-desktop@2.0.10) on Windows, Node v24.11.1
• @deepseek-ai/dsh-win32-process@0.1.5-rc.2
• @deepseek-ai/dsh-http-proxy@0.1.5-rc.2
• @deepseek-ai/dsh-subprocess@0.1.5-rc.2
• Proxy active (system proxy → http://proxyhk.huawei.com:8080)

Impact

• Any spawned PowerShell that touches the environment fails:
  • Get-ChildItem Env: → ArgumentException: 已添加项。字典中的关键字:“NO_PROXY” (duplicate key, case-insensitive dictionary)
  • Start-Process / Start-Job → same "已添加项" error when copying the environment
• Other tools that parse the env block into a case-insensitive map can misbehave.
• This also broke an unrelated session workflow (a pre-warm script using Start-Process).

Reproduction

1. On a Windows DSH where a proxy plugin publishes proxy variables (e.g. dsh-proxy-pro, or the built-in proxy), run any spawned tool (pwsh/bash) and check its raw environment block:

   cmd /c set | findstr /i "proxy"

   Expected: one no_proxy entry. Actual (excerpt):

   https_proxy=http://proxyhk.huawei.com:8080
   HTTPS_PROXY=http://proxyhk.huawei.com:8080
   http_proxy=http://proxyhk.huawei.com:8080
   HTTP_PROXY=http://proxyhk.huawei.com:8080
   no_proxy=localhost,127.0.0.1,::1,...
   NO_PROXY=localhost,127.0.0.1,::1,...
   NODE_USE_ENV_PROXY=1
   

2. Inside that child, run Get-ChildItem Env: (PowerShell) → duplicate-key ArgumentException.

Root-cause chain

1. Dual-case publication into process.env — @deepseek-ai/dsh-http-proxy (by design)

POLICY_ENV_NAMES (lib/index.js:29-33) publishes both casings per field:

const POLICY_ENV_NAMES = {
  httpProxy: ["http_proxy", "HTTP_PROXY"],
  httpsProxy: ["https_proxy", "HTTPS_PROXY"],
  noProxy: ["no_proxy", "NO_PROXY"]
};

writeProxyEnv (lib/index.js:364-375) assigns every name into process.env. On Windows, Node's process.env is case-insensitive (reads collide), but its key map retains both spellings (verified: after writing no_proxy then NO_PROXY, Object.keys(process.env) contains both keys; the last value wins). So the host env map carries two spellings of every proxy variable.

proxyEnvironmentForChild() (lib/index.js:491-503) additionally returns an overlay with both casings plus NODE_USE_ENV_PROXY: "1".

2. Verbatim copy into the spawn request — @deepseek-ai/dsh-subprocess

childEnvironment() (lib/index.js:51-55) copies Object.entries(process.env) verbatim (both spellings), then overlays proxyEnvironmentForChild() (both spellings again + NODE_USE_ENV_PROXY).

3. Missing case-fold de-dup in the raw env block — @deepseek-ai/dsh-win32-process ← the defect

encodeWindowsEnvironment (lib/index.js:319-327):

function compareWindowsEnvironmentKeys([left], [right]) {
  const foldedLeft = left.toUpperCase();   // case-insensitive comparator
  const foldedRight = right.toUpperCase();
  return foldedLeft < foldedRight ? -1 : foldedLeft > foldedRight ? 1 : 0;
}
function encodeWindowsEnvironment(env) {
  const strings = Object.entries(env).sort(compareWindowsEnvironmentKeys)
    .map(([key, value]) => `${key}=${value}`);   // ⚠️ sorts folded, but never drops the folded duplicate
  return Buffer.from(`${strings.join("\0")}\0\0`, "utf16le");
}

The comparator already folds case (toUpperCase), so no_proxy/NO_PROXY sort adjacently — but both entries are then serialized into the UTF-16LE block passed to CreateProcessW(..., 1028, environment, ...) (lib/index.js:616). Windows keeps both pairs verbatim → the child sees duplicate env keys.

Why direct Node tests don't reproduce it: libuv's spawn materialization collapses case-duplicates (verified empirically with spawnSync('cmd', ['/c','set'], { env: {...process.env, 'no_proxy': 'X', 'NO_PROXY': 'Y'} }) → child shows only NO_PROXY). Only the custom CreateProcessW path in dsh-win32-process preserves both.

Why removing the dsh-http-proxy plugin row did not help

The plugin row can be unmounted, but the package is still consumed as a library by two always-running components:

• dsh-subprocess imports proxyEnvironmentForChild at every spawn (its import line 2).
• dsh-proxy-pro peer-depends on @deepseek-ai/dsh-http-proxy and calls installProxyFromEnvironment.

They share ONE module instance: the profile's node_modules/@deepseek-ai/dsh-http-proxy is a junction into the app's node_modules/@deepseek-ai/dsh-http-proxy (same file, same SHA-256; Node resolves by realpath). So a single active policy state drives both the dispatcher and the per-spawn overlay. When dsh-proxy-pro installs a policy, it simultaneously activates the overlay that dsh-subprocess reads on every spawn — the two are not separable from the plugin side.

Proof it is live, not residue: NODE_USE_ENV_PROXY=1 appears in every spawned child, and it is produced only by proxyEnvironmentForChild (writeProxyEnv never writes it). A dead plugin cannot inject that into every new spawn; the shared instance is kept active by dsh-proxy-pro's install call.

Proposed fix (one location)

Prefer the uppercase spelling when a folded pair exists (matches what libuv's collapse keeps):

function encodeWindowsEnvironment(env) {
  const seen = new Map();
  for (const entry of Object.entries(env)) {
    const folded = entry[0].toUpperCase();
    const existing = seen.get(folded);
    if (existing === void 0 || (entry[0] === folded && existing[0] !== existing[0].toUpperCase())) {
      seen.set(folded, entry);
    }
  }
  const strings = [...seen.values()].sort(compareWindowsEnvironmentKeys)
    .map(([key, value]) => `${key}=${value}`);
  return Buffer.from(`${strings.join("\0")}\0\0`, "utf16le");
}

Alternatively/also: on Windows, dsh-http-proxy's writeProxyEnv could publish a single casing (Windows env is case-insensitive; the dual-case design exists for POSIX consumers' lowercase-first precedence and is meaningless there — but the spawner de-dup alone is sufficient and fixes every producer).

Notes

• The fix takes effect only for processes spawned after the patch; the Host must be restarted to reload the module.
• Local patch in a packaged install is overwritten on the next app update — an upstream fix is needed for durability.

---

中文摘要

• 现象：Windows 下 DSH spawn 的每个子进程环境块同时含 no_proxy 和 NO_PROXY（以及 http(s)_proxy 两拼写），PowerShell 的 Get-ChildItem Env: / Start-Process 报"已添加项，字典中的关键字:"NO_PROXY""。
• 根因：dsh-win32-process 的 encodeWindowsEnvironment 用 toUpperCase 折叠做排序比较，但排序后不折叠去重，两个拼写原样写入传给 CreateProcessW 的 UTF-16LE 环境块。Node 原生 libuv spawn 会折叠，所以只有 DSH 自定义 Windows spawn 会复现。
• 不是残留：双拼写由 dsh-subprocess 每次 spawn 时调用 dsh-http-proxy 的 proxyEnvironmentForChild() 现写（NODE_USE_ENV_PROXY=1 只有该函数注入，每个子进程都有，证明是现生成的）；dsh-proxy-pro 也 peer 依赖该库发布 env。
• 建议修复：在 encodeWindowsEnvironment 里按折叠键去重（保留大写拼写）；或让 dsh-http-proxy 在 Windows 上只发布一种拼写。