Fix Windows netstat encoding in agent bridge (#894)

packages/server/src/services/hermes/agent-bridge/hermes_bridge.py

@@ -14,6 +14,7 @@ import copy
 import hashlib
 import importlib.util
 import json
+import locale
 import os
 import queue
 import shutil
@@ -1649,6 +1650,13 @@ def _tcp_endpoint_port(endpoint: str) -> int | None:
         return None
 
 
+def _platform_text_encoding() -> str:
+    getencoding = getattr(locale, "getencoding", None)
+    if callable(getencoding):
+        return getencoding() or "utf-8"
+    return locale.getpreferredencoding(False) or "utf-8"
+
+
 def _windows_listening_pids_on_port(port: int) -> list[int]:
     if os.name != "nt":
         return []
@@ -1658,12 +1666,15 @@ def _windows_listening_pids_on_port(port: int) -> list[int]:
             check=False,
             capture_output=True,
             text=True,
+            encoding=_platform_text_encoding(),
+            errors="ignore",
             timeout=5,
         )
     except Exception:
         return []
+    stdout = result.stdout or ""
     pids: set[int] = set()
-    for line in result.stdout.splitlines():
+    for line in stdout.splitlines():
         parts = line.strip().split()
         if len(parts) < 5:
             continue

packages/server/src/services/hermes/agent-bridge/manager.ts

@@ -245,7 +245,7 @@ function tcpEndpointPort(endpoint: string): number | undefined {
 
 function windowsListeningPidsOnPort(port: number): number[] {
   try {
-    const output = execFileSync('netstat.exe', ['-ano', '-p', 'tcp'], { encoding: 'utf-8', windowsHide: true })
+    const output = execFileSync('netstat.exe', ['-ano', '-p', 'tcp'], { windowsHide: true }).toString('utf8')
     const pids = new Set<number>()
     for (const line of output.split(/\r?\n/)) {
       const parts = line.trim().split(/\s+/)

tests/server/agent-bridge-profile-env.test.ts

@@ -234,4 +234,55 @@ print(json.dumps({
       restored_glm: 'shell-glm',
     })
   })
+
+  it('handles Windows netstat output decode failures without crashing', async () => {
+    const result = await runBridgeProbe(`
+import importlib.util
+import json
+import os
+import sys
+
+spec = importlib.util.spec_from_file_location("hermes_bridge", os.environ["BRIDGE_PATH"])
+bridge = importlib.util.module_from_spec(spec)
+sys.modules["hermes_bridge"] = bridge
+spec.loader.exec_module(bridge)
+
+class EmptyStdoutResult:
+    stdout = None
+
+def fake_run_empty(*args, **kwargs):
+    return EmptyStdoutResult()
+
+class NetstatResult:
+    stdout = "  TCP    127.0.0.1:18765    0.0.0.0:0    LISTENING    4321\\r\\n"
+
+def fake_run_listener(*args, **kwargs):
+    return NetstatResult()
+
+original_name = bridge.os.name
+original_pid = bridge.os.getpid
+original_run = bridge.subprocess.run
+try:
+    bridge.os.name = "nt"
+    bridge.os.getpid = lambda: 1234
+    bridge.subprocess.run = fake_run_empty
+    empty = bridge._windows_listening_pids_on_port(18765)
+    bridge.subprocess.run = fake_run_listener
+    listener = bridge._windows_listening_pids_on_port(18765)
+finally:
+    bridge.os.name = original_name
+    bridge.os.getpid = original_pid
+    bridge.subprocess.run = original_run
+
+print(json.dumps({
+    "empty": empty,
+    "listener": listener,
+}))
+`)
+
+    expect(result).toEqual({
+      empty: [],
+      listener: [4321],
+    })
+  })
 })