NODERAWFS open() O_DIRECTORY / opendir() leak file descriptor on error

[tiran]

open() with O_DIRECTORY as used by opendir() leaks a file descriptor if the filename is not a directory (ENOTDIR).

Version of emscripten/emsdk:

emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.2 (a77b559a8b40b7e89fc8c17e41034128df9543e4)
clang version 14.0.0 (https://github.com/llvm/llvm-project 782c0dd1a1c235afb09a34e7da4a1267ead14765)
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: /emsdk/upstream/bin

reproducer

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>

#define FNAME "/etc/passwd"
#define LOOP 10000

int main(void) {
    int fd;
    for (int i=0; i < LOOP; i++) {
        fprintf(stderr, "%i\n", i);
        fd = open(FNAME, O_RDONLY|O_DIRECTORY|O_CLOEXEC);
        assert(fd < 0);
        if (errno != ENOTDIR) {
            perror("open O_DIRECTORY failed");
            return 1;
        }
    }
    return 0;
}

$ emcc -s NODERAWFS -o dirfdleak.js dirfdleak.c
$ node dirfdleak.js
...
open O_DIRECTORY failed: No file descriptors available

[sbc100]

Thanks for great repro cases with these bugs! This should be fairly easy fix. I don't have time to look at it right now so labeled as "help wanted".

[tiran]

You were right, it was a trivial fix.