The original caching implementation had an oversight in combination with
the new lifetime management in DOM for 8.3.
The modification counter is stored on the document object itself, but as
that can get deallocated when all references disappear, stale cache data
can be used. Normally this isn't a problem, unless getElementsByTagName is
called not on the document but on a child node. Fix it by moving caching
data into the ref object, which will outlive all nodes from a document
even if the document object disappears.
Closes GH-12338.
* PHP-8.3:
Fix compile error with -Werror=incompatible-function-pointer-types and old libxml2
Fix GH-10008: Narrowing occurred during type inference of ZEND_ADD_ARRAY_ELEMENT
Fix type error on XSLTProcessor::transformToDoc return value with SimpleXML
libxml2 prior to 2.9.8 had a different signature for xmlHashScanner.
This signature changed in e03f0a199a
Use an #if to work around the incompatible signature.
Closes GH-12326.
Fixes GHSA-3qrf-m4j2-pcrr.
To parse a document with libxml2, you first need to create a parsing context.
The parsing context contains parsing options (e.g. XML_NOENT to substitute
entities) that the application (in this case PHP) can set.
Unfortunately, libxml2 also supports providing default set options.
For example, if you call xmlSubstituteEntitiesDefault(1) then the XML_NOENT
option will be added to the parsing options every time you create a parsing
context **even if the application never requested XML_NOENT**.
Third party extensions can override these globals, in particular the
substitute entity global. This causes entity substitution to be
unexpectedly active.
Fix it by setting the parsing options to a sane known value.
For API calls that depend on global state we introduce
PHP_LIBXML_SANITIZE_GLOBALS() and PHP_LIBXML_RESTORE_GLOBALS().
For other APIs that work directly with a context we introduce
php_libxml_sanitize_parse_ctxt_options().
Change the way lifetime works in ext/libxml and ext/dom
Previously, a node could be freed even when holding a userland reference
to it. This resulted in exceptions when trying to access that node after
it has been implicitly or explicitly removed. After this patch, a node
will only be freed when the last userland reference disappears.
Fixes GH-9628.
Closes GH-11576.
* Implement iteration cache, item cache and length cache for node list iteration
The current implementation follows the spec requirement that the list
must be "live". This means that changes in the document must be
reflected in the existing node lists without requiring the user to
refetch the node list.
The consequence is that getting any item, or the length of the list,
always starts searching from the root element of the node list. This
results in O(n) time to get any item or the length. If there's a for
loop over the node list, this means the iterations will take O(n²) time
in total. This causes real-world performance issues with potential for
downtime (see GH-11308 and its references for details).
We fix this by introducing a caching strategy. We cache the last
iterated object in the iterator, the last requested item in the node
list, and the last length computation. To invalidate the cache, we
simply count the number of modifications made to the containing
document. If the modification number does not match what the number was
during caching, we know the document has been modified and the cache is
invalid. If this ever overflows, we saturate the modification number and
don't do any caching anymore. Note that we don't check for overflow on
64-bit systems because it would take hundreds of years to overflow.
Fixes GH-11308.
It's possible to categorise the failures into 2 categories:
- Changed error message. In this case we either duplicate the test and
modify the error message. Or if the change in error message is
small, we use the EXPECTF matchers to make the test compatible with both
old and new versions of libxml2.
- Missing warnings. This is caused by a change in libxml2 where the
parser started using SAX APIs internally [1]. In this case the
error_type passed to php_libxml_internal_error_handler() changed from
PHP_LIBXML_ERROR to PHP_LIBXML_CTX_WARNING because it internally
started to use the SAX handlers instead of the generic handlers.
However, for the SAX handlers the current input stack is empty, so
nothing is actually printed. I fixed this by falling back to a
regular warning without a filename & line number reference, which
mimicks the old behaviour. Furthermore, this change now also shows
an additional warning in a test which was previously hidden.
[1] 9a82b94a94
Closes GH-11162.
The Docbook parser module has been removed completely. Support for
XPointer locations (ranges and points) is disabled by default, and will
eventually be removed completely. Given that the maintainer comments
on the latter: "Be warned that this part of the code base is buggy and
had many security issues in the past", it seems to be prudent to no
longer build with XPointer locations support right away.
To be able to build against libxml2 2.10.0, we remove the export
definitions for Windows.
Closes GH-9358.
Add libxml_get_external_entity_loader(), which returns the currently
installed external entity loader, i.e. the value which was passed to
libxml_set_external_entity_loader() or null if no loader was installed
and the default entity loader will be used.
This allows libraries to save and restore the loader, controlling entity
expansion without interfering with the rest of the application.
Add macro Z_PARAM_FUNC_OR_NULL_WITH_ZVAL(). This allows us to get the
zval for a callable parameter without duplicating callable argument
parsing.
The saved zval keeps the object needed for fcc/fci alive, simplifying
memory management.
Fixes#76763.
@cname currently refers to the constant name in C. However, it is not always a (constant) name, but sometimes a function invocation, so naming it as @cvalue would be more appropriate.
