Some IPv6 hostnames can start with a colon (eg '::1'). This breaks
the IRC line format.

To work around this issue, prefix the hostname with a '0'. This
changes the representation of the IP but not its value.

See: https://todo.sr.ht/~taiite/senpai/109
---
 xirc/whox.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/xirc/whox.go b/xirc/whox.go
index 2e11813..ee5978c 100644
--- a/xirc/whox.go
+++ b/xirc/whox.go
@@ -80,6 +80,11 @@ func (info *WHOXInfo) set(k byte, v string) {
 }
 
 func GenerateWHOXReply(prefix *irc.Prefix, nick, fields string, info *WHOXInfo) *irc.Message {
+	if strings.HasPrefix(info.Hostname, ":") {
+		// The hostname cannot start with a colon as this would get parsed as a trailing parameter.
+		// IPv6 addresses such as "::1" are prefixed with a zero to ensure this.
+		info.Hostname = "0" + info.Hostname
+	}
 	if fields == "" {
 		return &irc.Message{
 			Prefix:  prefix,

base-commit: 959baa964f45b40fad239e21a246e3b963f9ca57
-- 
2.38.0

On Sun, Jan 22, 2023 at 12:32 AM delthas <delthas@dille.cc> wrote:
>
> Some IPv6 hostnames can start with a colon (eg '::1'). This breaks
> the IRC line format.
>
> To work around this issue, prefix the hostname with a '0'. This
> changes the representation of the IP but not its value.
>
> See: https://todo.sr.ht/~taiite/senpai/109
> ---
>  xirc/whox.go | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/xirc/whox.go b/xirc/whox.go
> index 2e11813..ee5978c 100644
> --- a/xirc/whox.go
> +++ b/xirc/whox.go
> @@ -80,6 +80,11 @@ func (info *WHOXInfo) set(k byte, v string) {
>  }
>
>  func GenerateWHOXReply(prefix *irc.Prefix, nick, fields string, info *WHOXInfo) *irc.Message {
> +       if strings.HasPrefix(info.Hostname, ":") {
> +               // The hostname cannot start with a colon as this would get parsed as a trailing parameter.
> +               // IPv6 addresses such as "::1" are prefixed with a zero to ensure this.
I wonder if the square brackets notation [::1] would make sense here?
> +               info.Hostname = "0" + info.Hostname
> +       }
>         if fields == "" {
>                 return &irc.Message{
>                         Prefix:  prefix,
>
> base-commit: 959baa964f45b40fad239e21a246e3b963f9ca57
> --
> 2.38.0
>

Edited to not mutate the field. Pushed, thanks!

On Monday, January 23rd, 2023 at 21:47, novenary <streetwalkermc@gmail.com> wrote:

> I wonder if the square brackets notation [::1] would make sense here?

No, this would confuse clients which parse the IP and don't expect
square brackets. See:
https://modern.ircdocs.horse/#rplwhoisuser-311

On Wed, Jan 25, 2023 at 1:05 AM Simon Ser <contact@emersion.fr> wrote:
> No, this would confuse clients which parse the IP and don't expect
> square brackets. See:
> https://modern.ircdocs.horse/#rplwhoisuser-311

I see, thanks for clarifying.