cygwin1.dll > 3.1.4: Program execution fails if (WSL-)symlink exists and is present in PATH

[Ken Brown]

On 12/1/2020 4:24 AM, Mattl Mario wrote:
> Hello,
> 
> Since cygwin1.dll version 3.1.5, I observed the following behavior:
> If a symbolic link is existing in the PATH environment, programs (external from Cygwin's system directory) using cygwin1.dll cannot be executed anymore.
> Possibly, because the Cygwin-DLL isn't found anymore.
> 
> Steps to reproduce:
> 
> cd /
> mkdir link_test
> cp /usr/bin/sed.exe link_test
> ln -s link_test test
> export PATH=/test:/link_test:/usr/bin:/bin
> 
> /link_test/sed cannot be executed
> $ ldd /link_test/sed
>          ntdll.dll => /cygdrive/c/WINDOWS/SYSTEM32/ntdll.dll (0x7ffffd960000)
>          KERNEL32.DLL => /cygdrive/c/WINDOWS/System32/KERNEL32.DLL (0x7ffffd140000)
>          KERNELBASE.dll => /cygdrive/c/WINDOWS/System32/KERNELBASE.dll (0x7ffffa8e0000)
>          SYSFER.DLL => /cygdrive/c/WINDOWS/System32/SYSFER.DLL (0x550c0000)
> 
> -> no cygwin- DLLs found
> 
> If I delete the symbolic link
> $ ll test
> lrwxrwxrwx 1 mmattl Users 9 Dec  1 10:14 test -> link_test/
> simply with
> rm test
> 
> everything is working fine; sed can be executed
> $ /link_test/sed
> Usage: /link_test/sed [OPTION]... {script-only-if-no-other-script} [input-file]...
> [...]
> And
> 
> $ ldd /link_test/sed
>          ntdll.dll => /cygdrive/c/WINDOWS/SYSTEM32/ntdll.dll (0x7ffffd960000)
>          KERNEL32.DLL => /cygdrive/c/WINDOWS/System32/KERNEL32.DLL (0x7ffffd140000)
>          KERNELBASE.dll => /cygdrive/c/WINDOWS/System32/KERNELBASE.dll (0x7ffffa8e0000)
>          SYSFER.DLL => /cygdrive/c/WINDOWS/System32/SYSFER.DLL (0x550c0000)
>          cygwin1.dll => /usr/bin/cygwin1.dll (0x180040000)
>          cygintl-8.dll => /usr/bin/cygintl-8.dll (0x3f7110000)
>          cygiconv-2.dll => /usr/bin/cygiconv-2.dll (0x3f7160000)
> 
> It would be great if you could give some advice to this issue.

I think this was fixed by commit 4b4fffe0f2390be6a5be27b6a3ceaa212a3724b2, but I 
don't have time to check carefully, and I'm going to be AFK for a few days 
starting tomorrow.

Corinna, could you build a snapshot for Mario to test?  If it's not fixed, I'll 
be able to look it within a week or so.

Thanks.

Ken