C:\Temp> echo "hello" > f1
C:\Temp> mklink /H f1 f2

C:\Temp>type c1.cpp
#include <filesystem>

int main() {
   std::filesystem::rename("f1","f2");
}

C:\Temp>cl /EHsc /W4 /std:c++17 .\c1.cpp
Microsoft (R) C/C++ Optimizing Compiler Version 19.23.28019.1 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

c1.cpp
Microsoft (R) Incremental Linker Version 14.23.28019.1
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:c1.exe
c1.obj

C:\Temp>.\c1.exe

Expected behavior

C:\Temp> dir /B
f1
f2


Observed behavior

C:\Temp> dir /B
f2

C:\Temp> mkdir mydir
C:\Temp> echo "hello" > mydir\f1
C:\Temp> mkdir emptydir

C:\Temp>type c2.cpp
#include <filesystem>

int main() {
   std::filesystem::rename("mydir","emptydir");
}

C:\Temp>cl /EHsc /W4 /std:c++17 .\c2.cpp
Microsoft (R) C/C++ Optimizing Compiler Version 19.23.28019.1 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

c2.cpp
Microsoft (R) Incremental Linker Version 14.23.28019.1
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:c2.exe
c2.obj

C:\Temp>.\c2.exe

Expected behavior

C:\Temp> dir /B /S
C:\Temp\emptydir
C:\Temp\emptydir\f1


Observed behavior

C:\Temp> dir /B /S
C:\Temp\emptydir
C:\Temp\mydir
C:\Temp\mydir\f1

https://github.com/microsoft/STL/commit/e745bad3b1d05b5b19ec652d68abb37865ffa454