This macro is obsolete, see `man feature_test_macros`.

Abort earlier in xmlTextReaderRead if an error was raised.

Only fragment identifiers are an error.

This removes the last user of xmlErrMsg*. Now every error reported by
the parser should result in one of ctxt->wellFormed, ctxt->nsWellFormed
or ctxt->valid being set to zero.

Entity references point to entities in the DTD, so only unlink the DTD
and don't destroy it.

Add a missing bounds check.

Fixes #720.

Regressed in 74c84a8c.

Remove unnecessary globals and make some local.

Remove unnecessary calls to xmlTextReaderSetParserProp.

Remove unused "oldout" code.

Fix skipArgs.

Merge a few code paths, making options like --valid or --htmlout work
with some other options.

Improve error handling.

`ctxt->input` can be NULL after commit 61b4c42f.

Fix corner cases like 'xmllint --encode --maxmem 123'.

Also fixes --path without LIBXML_VALID_ENABLED.

Prepare for fuzzing.

- Add standalone declaration
- Add doctype declaration
- Expand ATTLIST matrix in xml.dict

Make sure that parent is an element when calling
xmlValidGetValidElements.

This is only a debugging aid but also useful when fuzzing.

This can happen in "walker" mode.

Search parent inputs of internal parameter entities for base URI.

Fixes a long-standing bug, which manifested in a different way after
commit 955c177f. Reproduce with

    xmllint --noent xmlconf/eduni/errata-2e/E18.xml

When parsing with XML_PARSE_DTDLOAD, missing entities are always an
error.

Also consolidate behavior when validating. See b717abdd.

We never want to create entity reference nodes if entity substitution
is enabled. This also applies to undeclared entities.

These don't seem to be used by downstream code.

It's possible to create references to predefined entities using the tree
API. This edge case was exposed by making predefined entities const in
commit 63ce5f9a.

xmlNewCharRef also tries to handle strings like '&name;' but in
xmlNodeParseContentInternal, we really want to use the possibly invalid
name without modification. Otherwise, content like '&"' could
create a reference to a predefined entity.

The tutorial was moved to the Wiki:

https://gitlab.gnome.org/GNOME/libxml2/-/wikis/Tutorial