"Unable to resolve host" when using international domain name

  • Hi,

    I could not find the project’s bug tracker on gitlab, so I am reporting this bug through the forum.

    When entering a valid HTTP URL where the domain name contain international characters, ICSDroid displays error “Unable to resolve host”

    Example URL: https://café-vie-privée.fr/calendar.ics


  • Found a workaround. It’s not straightforward, but I’m sharing this because the information might help fix the issue.

    By reading some online document, I learned the standard for international domain name defines a method for normalizing those domains with non-ascii characters, named “ToASCII”.

    For testing purpose, I used the tunycode.js library which provide this function.

    punycode.toASCII(‘café-vie-privée’) => “xn–caf-vie-prive-dhbj”

    After generating this normalized version, I was finally able to subscribe the desired ICS calender with ICSDroid:
    https:// xn–caf-vie-prive-dhbj . fr /calendar.ics

    Update: I was force to add spaces, because bitfire automatically converts normalized ASCII URL back to the unicode URL…

  • This post is deleted!
  • developer


    @guillaumeT1 said:

    I could not find the project’s bug tracker on gitlab, so I am reporting this bug through the forum.

    There is none. The forum is the right place to discuss this. Also, I’d consider it a missing feature (IDN) and not a bug.

    Java’s HttpURLConnection doesn’t handle IDN by default. It should be possible to convert host names by IDN.toASCII(), but I wonder why this is not implemented by default in Java URLs. Maybe because of security reasons, but I guess that wouldn’t apply here.

    I’ll have a look at this… in the meanwhile, please just use the ASCII name of the domain.

  • Hi,

    That make sense. So please consider this a feature request, as opposed to a bug report.

    Using ASCII is fine for now, there are few french-speaking websites using IDN.
    But there probably many arab/chineese/russian-speaking websites that do, so it may be more annoying for those users.

    N.B. I’ve sent a flattr micro-donation as a gesture of support


Similar topics