Link::existsSync() fails on windows when symlink to a folder exists, but with different case.

[sohrab-ikran]

Link::existsSync() fails on windows when symlink to a folder exists, but with different case.

For example, the Link object is created with path A:\b\Hello. But the symlink to the folder already exists as A:\b\hello.

• Dart version and tooling diagnostic info (dart info)
  dart info

General info

• Dart 3.5.3 (stable) (Wed Sep 11 16:22:47 2024 +0000) on "windows_x64"
• on windows / "Windows 10 Pro" 10.0 (Build 22631)
• locale is en-IN

Process info

Memory	CPU	Elapsed time	Command line
14 MB	--		dart.exe
437 MB	--		dart.exe
14 MB	--		dart.exe
154 MB	--		dart.exe
93 MB	--		dart.exe

• Whether you are using Windows, macOS, or Linux (if applicable)
  Windows
• Whether you are using Chrome, Safari, Firefox, Edge (if applicable)
  Not applicable

[dart-github-bot]

Summary: The Link::existsSync() method on Windows incorrectly fails to detect a symlink to a folder when the case of the symlink path differs from the actual folder path. For example, a symlink named "A:\b\Hello" fails to find a folder named "A:\b\hello".

[mraleph]

You would need to provide a reproduction. I have tried simple test:

import 'dart:io';

void main() async {
  Link('c:\\src\\aaa').createSync('C:\\src\\dart');
  print(Link('c:\\src\\aAa').existsSync());
}

and it does not reveal any case sensitivity.

That being said: it might be that A:\b\Hello is treated in a case-sensitive manner by the OS due to various reasons. You can try to check that using command like this (see https://learn.microsoft.com/en-us/windows/wsl/case-sensitivity#inspect-current-case-sensitivity):

fsutil.exe file queryCaseSensitiveInfo <path>