dash does not support multi-digit file descriptors

Binary package hint: dash

Found in dash version 0.5.4-8ubuntu1.

The POSIX specification for "Shell Command Language" at http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_07 says that multi-digit file descriptors are allowed, i.e. 10, 20, 25, etc..

The relevant part of the specification is
"The redirection operator:

[n]>&word

shall duplicate one output file descriptor from another, or shall close one. If word evaluates to one or more digits, the file descriptor denoted by n, or standard output if n is not specified, shall be made to be a copy of the file descriptor denoted by word ..."

Dash seems to only support single digit fds:
kstemen@kyle-vmserver:~$ sh 3>3.txt 9>9.txt 10>10.txt 11>11.txt
$ ls /proc/$$/fd
0 1 10 11 12 2 3 9
$ echo test >&3
$ echo test >&9
$ echo test >&10
sh: Syntax error: Bad fd number
$ echo test >&11
sh: Syntax error: Bad fd number
$

This seems to be caused by fixredir in parser.c:
void fixredir(union node *n, const char *text, int err)
    {
    TRACE(("Fix redir %s %d\n", text, err));
    if (!err)
        n->ndup.vname = NULL;

    if (is_digit(text[0]) && text[1] == '\0')
        n->ndup.dupfd = digit_val(text[0]);
    else if (text[0] == '-' && text[1] == '\0')
        n->ndup.dupfd = -1;
    else {

        if (err)
            synerror("Bad fd number");
        else
            n->ndup.vname = makename();
    }
}