Setting up an empty default handler is not only useless, but actually
harmful, since internal entity-references are not resolved anymore.
From the libexpat docs[1]:
| Setting the handler with this call has the side effect of
| turning off expansion of references to internally defined general
| entities. Instead these references are passed to the default
| handler.
[1] <https://www.xml.com/pub/1999/09/expat/reference.html#setdefhandler>
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.
The issue is caused by an integer overflow when the `long` passed as
XML_OPTION_SKIP_TAGSTART is assigned to `xml_parser::toffset` which is
declared as `int`. We can simply work around this issue, by clipping
resulting negative values to 0 (and raising a notice in this case), because
the reasonable range for this value is certainly catered to by positive
`int`s.
However, there still remains the issue that `xml_parser::toffset` is later
added to `char *`s, which can cause OOB reads, so we make sure that the
upper bound never exceeds the strlen(). We eschew optimizing `SKIP_TAGSTART`
wrt. to the potentially duplicate strlen() call, because that code path is
unexpected anyway.
PHP_VERSION_ID
PHP_API_VERSION
ZEND_MODULE_API_NO
PHP_MAJOR_VERSION, PHP_MINOR_VERSION
ZEND_ENGINE_2
I've left litespeed alone, as it seems to genuinely maintain support
for many PHP versions.