microsoft / microsoft/STL

`<filesystem>`: MSVC's `path` conversion from wide to narrow throws an exception (`fs::path(L"要").string()`)

Open
#5,093 7 comments 1 reaction 0 assignees View on GitHub

Nobody has claimed this yet.

filesystem info needed
Dominant language
C++
Stars
11.1k
Forks
1.7k
Avg merge
4d 15h
Merged PRs (30d)
22

Description

Describe the bug

MSVC's std::filesystem::path conversion from wide to narrows crashing with the following snippet:

#include <iostream>
#include <filesystem>
int main() {
    std::filesystem::path(L"要らない.exe").string();
    std::cout << "Hello World!\n";
}

I also tried in a fresh sandbox with fresh latest VS Community installation and crash is happening on both builds x86|x64 Debug|Release:
Microsoft C++ exception: std::system_error at memory location

Also tried compiling with and without unicode enabled. Same behavior.

Expected behavior

conversion should succeed and not crash the program.

STL version

Microsoft Visual Studio Community 2022 (64-bit) - Current
Version 17.11.1

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the failure with the provided std::filesystem::path(L"要らない.exe").string() snippet on Visual Studio 2022 17.11.1 across the reported configurations. Trace the wide-to-narrow path conversion and verify that the conversion completes without throwing and the program reaches the Hello World output.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
operating-systems
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
48/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.