Parent directory (..) does not work on windows

[matklad]

Zig Version

0.10.1

Steps to Reproduce and Observed Behavior

pub fn main() !void {
    var current = try std.fs.cwd().openDir(".", .{}); // dup cwd so that the caller can close
    errdefer current.close();

    var level: u32 = 0;
    while (level < 16) : (level += 1) {
        std.debug.print("{s}\n", .{try current.realpathAlloc(std.heap.page_allocator, ".")});
        var parent = try current.openDir("..", .{});
        current.close();
        current = parent;
    }
}

PS C:\Users\matklad\p\tigerbeetle> .\zig\zig.exe run src/shell.zig
C:\Users\matklad\p\tigerbeetle
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p
C:\Users\matklad\p

Expected Behavior

Go up! :-)

[matklad]

Repros on 0.11 as well.

cc @marler8997 as the author of #7664

[squeek502]

I know what's going on here. The path is always resolved against the cwd (via RtlGetFullPathName_U) when TooManyParentDirs occurs in std.os.windows.normalizePath. Will look into potential solutions.

[matklad]

While we are at it, might it make sense to add fn open_parent(dir: std.fs.Dir) !?std.fs.Dir? might communicate the intention more precisely for this case!

[squeek502]

Got something working:

C:\Users\Ryan\Programming\Zig\tmp
C:\Users\Ryan\Programming\Zig
C:\Users\Ryan\Programming
C:\Users\Ryan
C:\Users
C:\
C:\
C:\
C:\
C:\
C:\
C:\
C:\
C:\
C:\
C:\

will have a PR sometime soon.

[squeek502]

PR made: #16783