From acd67eaa75ac68d46a4c41ebbc7676572c0353a7 Mon Sep 17 00:00:00 2001
From: Merith <merith@merith.xyz>
Date: Wed, 4 Mar 2026 04:37:32 -0800
Subject: [PATCH] adress copilot reviews

---
 CMakeLists.txt                                |  6 +++--
 .../Windows64/Windows64_Minecraft.cpp         | 26 ++++++++++++++++---
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index feaf1d5c1..4b6b43b13 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -62,8 +62,10 @@ if(MSVC)
   # Docker and piped output in server mode).  WinMainCRTStartup keeps the
   # WinMain entry point.  Client mode calls FreeConsole() to detach.
   target_link_options(MinecraftClient PRIVATE
-    /SUBSYSTEM:CONSOLE /ENTRY:WinMainCRTStartup
-    $<$<CONFIG:Release>:/LTCG /INCREMENTAL:NO>
+    /SUBSYSTEM:CONSOLE
+    /ENTRY:WinMainCRTStartup
+    $<$<CONFIG:Release>:/LTCG>
+    $<$<CONFIG:Release>:/INCREMENTAL:NO>
   )
 endif()
 
diff --git a/Minecraft.Client/Windows64/Windows64_Minecraft.cpp b/Minecraft.Client/Windows64/Windows64_Minecraft.cpp
index 91a1366ca..a95fd56fc 100644
--- a/Minecraft.Client/Windows64/Windows64_Minecraft.cpp
+++ b/Minecraft.Client/Windows64/Windows64_Minecraft.cpp
@@ -228,9 +228,29 @@ static BOOL WINAPI HeadlessServerCtrlHandler(DWORD ctrlType)
 
 static void SetupHeadlessServerConsole()
 {
-	// The exe is now linked as /SUBSYSTEM:CONSOLE, so it inherits the parent's
-	// console automatically.  We just need to re-open the CRT streams so that
-	// printf/scanf go through the console and set up our Ctrl handler.
+	// The exe is linked as /SUBSYSTEM:CONSOLE, so it normally inherits the
+	// parent's console.  However, if launched with DETACHED_PROCESS or
+	// CREATE_NO_WINDOW the handles may be invalid.  Verify before redirecting
+	// the CRT streams to avoid leaving them in a broken state.
+	HANDLE hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
+	HANDLE hStdIn  = GetStdHandle(STD_INPUT_HANDLE);
+	bool hasConsole =
+		hStdOut != NULL && hStdOut != INVALID_HANDLE_VALUE &&
+		hStdIn  != NULL && hStdIn  != INVALID_HANDLE_VALUE;
+
+	if (!hasConsole)
+	{
+		if (!AttachConsole(ATTACH_PARENT_PROCESS))
+		{
+			if (!AllocConsole())
+			{
+				// No console available at all; skip stream redirection.
+				SetConsoleCtrlHandler(HeadlessServerCtrlHandler, TRUE);
+				return;
+			}
+		}
+	}
+
 	FILE* stream = NULL;
 	freopen_s(&stream, "CONIN$", "r", stdin);
 	freopen_s(&stream, "CONOUT$", "w", stdout);