From db79efcb7b75f50d4314bfb3af86e38ea947358b Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Thu, 13 Mar 2025 16:37:18 +0100
Subject: [PATCH] fix: Fix log file locking on Windows

Fixes #1575.

(cherry picked from commit 1581d9a3c9f7894334aa5e0745fc4d3d3bbdacd3)
---
 src/ccache/util/filelock.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/ccache/util/filelock.cpp b/src/ccache/util/filelock.cpp
index e6874966..379afa5e 100644
--- a/src/ccache/util/filelock.cpp
+++ b/src/ccache/util/filelock.cpp
@@ -1,4 +1,4 @@
-// Copyright (C) 2024 Joel Rosdahl and other contributors
+// Copyright (C) 2024-2025 Joel Rosdahl and other contributors
 //
 // See doc/AUTHORS.adoc for a complete list of contributors.
 //
@@ -64,7 +64,11 @@ FileLock::acquire()
   if (handle == INVALID_HANDLE_VALUE) {
     return false;
   }
-  m_acquired = LockFile(handle, 0, 0, MAXDWORD, MAXDWORD) != 0;
+  OVERLAPPED overlapped{};
+  m_acquired =
+    LockFileEx(
+      handle, LOCKFILE_EXCLUSIVE_LOCK, 0, MAXDWORD, MAXDWORD, &overlapped)
+    != 0;
 #else
   struct flock lock;
   memset(&lock, 0, sizeof(lock));
-- 
2.47.2