Bug#970579: libvte-2.91-0: OSC 7 does not work with hostname starting with a digit

[Simon McVittie]

Control: retitle -1 libvte-2.91-0: OSC 7 does not work with hostname starting with a digit
Control: reassign -1 libglib2.0-0
Control: affects -1 + libvte-2.91-0

On Sat, 19 Sep 2020 at 10:13:26 +0200, Tobias Bengfort wrote:
> I temporarily changed my hostname from "2902toc" to "test" and it also
> worked. So maybe libvte doesn't like my hostname?

This appears to be because libvte-2.91-0 uses g_filename_from_uri() to
convert the argument of the VTECWD sequence into a filename, and that
function does not allow hostnames that start with a digit:

    $ python3
    >>> from gi.repository import GLib
    >>> GLib.filename_from_uri('file:///etc')
    ('/etc', hostname=None)
    >>> GLib.filename_from_uri('file://two902toc/etc')
    ('/etc', hostname='two902toc')
    >>> GLib.filename_from_uri('file://2902toc/etc')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    gi.repository.GLib.Error: g_convert_error: The hostname of the URI “file://2902toc/etc” is invalid (4)

Specifically, hostname_validate() checks that the first character of
the hostname is a letter. As per RFC 1123 it should probably allow
either a letter or a digit in that position.

As a practical matter, I would suggest choosing hostnames that do not
start with digits if possible, because this is likely to be far from
the only bug involving hostnames starting with digits.

    smcv