[xml] xmlCtxtReadFile and IPv6

[Steve Wolf <stevewolf6 gmail com>]

I just submitted a bug and proposed fix:

https://bugzilla.gnome.org/show_bug.cgi?id=694185

According to the instructions at http://xmlsoft.org/bugs.html, I'm
supposed to notify this list.  I apologize if this wasn't necessary.

> From the bug description:

> RedHat Bug 624626 discusses the new behavior of libxml regarding brackets
> around IPv6 addresses.  In earlier versions such as 2.6.27, uri.c stripped the
> brackets (e.g. uri->server == "fdf2:1e39:73d1:934e::119"); in the current
> version it returns IPv6 addresses with brackets intact (e.g. uri->server ==
> "[fdf2:1e39:73d1:934e::119]").
>
> Thus in 2.9.0, xmlCtxtReadFile() has a problem when it is passed a URL
> containing a literal IPv6 address.  xmlCtxReadFile() and its subroutines pass
> uri->server unchanged to getaddrinfo(), which doesn't recognize a bracketed
> IPv6 address, so the read fails.  In the sample program attached, it returns:
>
> error : No such file or directory
> I/O warning : failed to load external entity
> "http://[fdf2:1e39:73d1:934e::119:4567/Manifest.xml";

> The attached patch strips the brackets from the uri->server value, and allows
> the sample program to execute without error.

Regards,
Steve