Merge "read() can return fewer bytes than requested" into main

#include <private/android_filesystem_config.h>

#include <private/fs_config.h>

#include <android-base/file.h>

#include <string>

/* NOTES

**

** - see https://www.kernel.org/doc/Documentation/early-userspace/buffer-format.txt

    if(lstat(in, &s)) err(1, "could not stat '%s'", in);

    if(S_ISREG(s.st_mode)){

        int fd = open(in, O_RDONLY);

        if(fd < 0) err(1, "cannot open '%s' for read", in);

        char* tmp = (char*) malloc(s.st_size);

        if(tmp == 0) errx(1, "cannot allocate %zd bytes", s.st_size);

        if(read(fd, tmp, s.st_size) != s.st_size) {

            err(1, "cannot read %zd bytes", s.st_size);

        std::string content;

        if (!android::base::ReadFileToString(in, &content)) {

            err(1, "cannot read '%s'", in);

        }

        _eject(&s, out, olen, tmp, s.st_size);

        free(tmp);

        close(fd);

        _eject(&s, out, olen, content.data(), content.size());

    } else if(S_ISDIR(s.st_mode)) {

        _eject(&s, out, olen, 0, 0);

        _archive_dir(in, out, ilen, olen);