From d68a5d3f3c828217c9dc66309ce82ddf848c4e56 Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Tue, 1 Apr 2025 15:09:37 -0400
Subject: [PATCH] SystemTools: Comment why ChangeDirectory does not use UNC for
 long paths

Issue: cmake/cmake#25936
---
 SystemTools.cxx | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/SystemTools.cxx b/SystemTools.cxx
index ef16256..463ff71 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -329,6 +329,9 @@ inline char const* Getcwd(char* buf, unsigned int len)
 }
 inline int Chdir(std::string const& dir)
 {
+  // We cannot use ToWindowsExtendedPath here because that causes a
+  // UNC path to be recorded as the process working directory, and
+  // can break child processes.
   return _wchdir(KWSYS_NAMESPACE::Encoding::ToWide(dir).c_str());
 }
 inline void Realpath(std::string const& path, std::string& resolved_path,
-- 
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