implement ".." (parent directory) for std.fs.Dir.openDir on Windows

[andrewrk]

zig/lib/std/fs.zig

Lines 768 to 772 in e839250

	if (sub_path_w[0] == '.' and sub_path_w[1] == '.' and sub_path_w[2] == 0) {
	// If you're looking to contribute to zig and fix this, see here for an example of how to
	// implement this: https://git.midipix.org/ntapi/tree/src/fs/ntapi_tt_open_physical_parent_directory.c
	@panic("TODO opening '..' with a relative directory handle is not yet implemented on Windows");
	}

example zig code:

const std = @import("std");

pub fn main() anyerror!void {
    var it = try std.fs.walkPath(std.heap.direct_allocator, "..");
    while (try it.next()) |entry| {
        std.debug.warn("{}\n", entry.path);
    }
}

> zig.exe build-exe test.zig
> test.exe 
TODO opening '..' with a relative directory handle is not yet implemented on Windows

[Leguu]

Is it possible to evaluate just . as an absolute file path and then remove the final bit in order to get the directory of ..?

E.g; . is C:\Users\Legu\, and therefore stripping the last bit gives you C:\Users

I'm new to contributing, so I hope this makes sense.

[Andoryuuta]

This appears to have been implemented by changes made in the last ~2 years.

I have just tested the following from the latest commit in the master branch (#5d14590), and can confirm it's working as expected:

const std = @import("std");

pub fn main() !void {
    const dir = try std.fs.cwd().openDir("..", .{.iterate = true});

    var walker = try dir.walk(std.heap.page_allocator);
    defer walker.deinit();

    while (try walker.next()) |entry| {
        std.debug.print("path: {s}\n", .{entry.path});
    }
}

[marler8997]

Yeah I believe this was implemented with #7664