Given that ICU is a set of lively developed libraries, that ICU 50.1
has been released on 2012-11-05, and PHP 7.4 is scheduled to be
released seven years after it, we consider it appropriate to ditch
these legacy versions.
Particularly, that would be a reasonable groundwork to implement part
two of the “Deprecate and remove INTL_IDNA_VARIANT_2003” RFC[1], namely
to default idn_to_ascii()'s and idn_to_utf8()'s $variant parameter to
INTL_IDNA_VARIANT_UTS46, which is not defined in ICU < 4.6.
See also the related discussion on internals@[2].
[1] <https://wiki.php.net/rfc/deprecate-and-remove-intl_idna_variant_2003>
[2] <http://news.php.net/php.internals/101626>ff
As stated by RFC 5890, U-Labels might be up to 252 Unicode code points
long. This can be fixed in 7.1+ as well, but there might potentially be
issues in some existing apps expecting the output to be max 255 octets
long. Thus it seems to be safer to not to touch stable branches.
The $Id$ keywords were used in Subversion where they can be substituted
with filename, last revision number change, last changed date, and last
user who changed it.
In Git this functionality is different and can be done with Git attribute
ident. These need to be defined manually for each file in the
.gitattributes file and are afterwards replaced with 40-character
hexadecimal blob object name which is based only on the particular file
contents.
This patch simplifies handling of $Id$ keywords by removing them since
they are not used anymore.
We don't actually fix this issue wrt. the empty $info array, because it is
not clear what this array should contain and we're concerned about the
potential BC break, but at least we fix the inconsistent handling of
resulting domains with 255 bytes (which raise an error), and longer domains
(which just return FALSE), what has to be considered a very minor BC break
if at all.