From bdba84fdf62cd9916a289bcda59e52529194b6d8 Mon Sep 17 00:00:00 2001
From: Haowen Liu <lhw@lunacd.com>
Date: Sat, 26 Apr 2025 16:26:42 -0400
Subject: [PATCH] Proper implementation of wait() on Windows

This commit makes sure:
1. WaitForSingleObject returns with expected
code before proceeding.
2. Process handle is properly closed.
---
 subprocess.hpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/subprocess.hpp b/subprocess.hpp
index 3975eb6..073f075 100755
--- a/subprocess.hpp
+++ b/subprocess.hpp
@@ -1423,11 +1423,18 @@ inline int Popen::wait() noexcept(false)
 #ifdef __USING_WINDOWS__
   int ret = WaitForSingleObject(process_handle_, INFINITE);
 
+  // WaitForSingleObject with INFINITE should only return when process has signaled
+  if (ret != WAIT_OBJECT_0) {
+    throw OSError("Unexpected return code from WaitForSingleObject", 0);
+  }
+
   DWORD dretcode_;
 
   if (FALSE == GetExitCodeProcess(process_handle_, &dretcode_))
       throw OSError("Failed during call to GetExitCodeProcess", 0);
 
+  CloseHandle(process_handle_);
+
   return (int)dretcode_;
 #else
   int ret, status;