Endless tree with System.IO.Directory.GetFiles

[LiranBinshtok]

Description

when using Directory.GetFiles ( with all directories flag ) on a folder that contains subfolder and one of those holds a symbolic link
to the parent folder, the result will be an endless tree.

run this at terminal:
mkdir ~/test
mkdir ~/test/test1
mkdir ~/test/test1/test2
ln -s ~/test ~/test/test1/test2

then run this code:

namespace Tests { class Program { static void Main(string[] args) { var res = Directory.GetFiles("/Users/{youruser}/test","", SearchOption.AllDirectories); } } }

result: endless tree.

expected behavior: skip symbolic link

Configuration

.net core version: 3.1
OS: mac OS 11.2.1 Big Sur

Regression?

Other information

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[Symbai]

According to the docs this is an expected behavior: https://docs.microsoft.com/en-us/dotnet/api/system.io.searchoption?view=net-5.0#remarks

[Zintom]

MSDN states this is expected behaviour, granted it would be nice to have a SearchOption.IgnoreSymLinks, or even a IgnoreRecursiveSymLinks option which would check if the Symbolic Link happens to point to a directory which has already been checked.

[iSazonov]

PowerShell has this many years. You can explicitly set FollowSymlink switch to follow symlinks in dir (aka Get-ChildItems).
But it is very expensive because this automatically turns on cycle checks for recursion.
It is very native design.

So if we want SearchOption.IgnoreSymLinks we should discuss SearchOption.CheckCycles too.
(For reference #24271 (comment))

[jozkee]

This should be addressed with #52666.
Closing as duplicate.