cd fails for directory without read permission, displays `Permission denied`

[TheJonny]

cd fails for directory without read permission, displays `Permission denied`

[TheJonny]

here an strace.

strace.log

the only EACCES occurs in line 2947, followed by printing the error message:

2947 openat(AT_FDCWD, "/srv", O_RDONLY|O_CLOEXEC) = -1 EACCES (Permission denied)
2948 write(2, "cd: Permission denied: '/srv'\n", 30) = 30

[TheJonny]

builtins/cd.rs calls fds::wopen_dir, which calls fds::open_dir, which sets O_RDONLY. changing it to O_PATH works for me on Linux, but is neither portable nor correct for a function called open_dir

But it looks like open_dir is only used in cd and in the parser to initialize LibraryData::cwd_fd.
It also seems like cwd_fd is never read (grep does not find usages, and it still builds when changing it to pub(crate) in struct LibraryData.)

so can we just remove the functions, skip the filedescriptor and directly chdir? this would be portable to platforms without O_PATH (like it seems, macos) or O_SEARCH (all platforms, even if this is specified by posix)

[TheJonny]

If we want to keep cwd_fd, we can first chdir and then open(".", ...) (as done in the Parser's constructor).
As cwd_fd is an Option, this would be ok to fail.

The flag can be O_SEARCH, O_SEARCH or O_RDONLY, whatever is supported on the platform.