1.3.22: executing relative symlinks on network shares

[Daniel Villeneuve <danielv at ad-opt dot com>]

Hi,

I have a problem when trying to execute relative symlinks
located on network shares: when I create such a symlink,
Cygwin does not find the pointed-to executable and continues
down the PATH.  Bash does not have the problem because I
think it does not rely on find_exec to find executables, but
scans the PATH itself. Perl and the smaller C program
given hereafter use execvp (which calls find_exec) and fail.

cat >callgcc.c <<EOF
#include <unistd.h>
#include <stdlib.h>

int main(void)
{
  char *argv[] = { "gcc", "--version", NULL };
  execvp("gcc", argv);
  perror("callgcc");
  exit(EXIT_FAILURE);
}
EOF

To illustrate the problem, I need to have access to a
network share directly mounted (via mount) using the
Windows share name (//machine/account).

Here is a complete setup.  My $HOME is not on the same
network share than the one I'm using for the example.

mount -buf '//machine/account' /home/account
cd /home/account
mkdir t
cd t
ln -s /usr/bin/gcc-2.exe foo.exe
ln -s ../t/foo.exe gcc.exe

cd $HOME
gcc -o callgcc callgcc.c # the small program above
PATH=/home/account/t:$PATH ./callgcc
=> gcc 3.2 !

The relevant output of strace is in attachment here.

Attachment: fe-without-netuse
Description: Binary data

The output should be gcc 2.95.3-10, since the gcc.exe in
/home/account/t points to foo.exe which points to
/usr/bin/gcc-2.exe.

If I do the following:

net use r: '\\machine\account'
umount -u /home/account
mount -buf r: /home/account

the behavior is correct.

The relevant output of strace is in attachment here.

Attachment: fe-with-netuse
Description: Binary data

The problem seems to be around symlink_info::check,
performing an unwanted side effect on the analyzed path in
one case but not the other.

The output of "cygcheck -s" is in attachment here.

Attachment: check
Description: Binary data

Let me know if more information is needed.

Thanks for your time,
--
Daniel Villeneuve
AD OPT Technologies Inc.

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