[Shaisolaris]

Purpose / Goal

XMLValidator.validate reports "XML declaration allowed only at the start of the document." for a declaration before the root, but accepts one inside an element:

Input:

XMLValidator.validate('<foo><?xml version="1.0"?></foo>')
XMLValidator.validate('<foo>bar<?xml?></foo>')

Expected: InvalidXml error, "XML declaration allowed only at the start of the document."
Actual: true for both. libxml2 rejects both documents.

Cause: inside tag content the validator calls readPI(xmlData, ++i), which passes the index of the ? instead of the index after <?. readPI then reads the target as ?xml, so the tagname === 'xml' check never matches. The top-level call already passes the position after <?; this change does the same in tag content.

Type

• Bug Fix
• Refactoring / Technology upgrade
• New Feature

Testing:

• The new spec in spec/validator_spec.js fails before the change and passes after.
• npx jasmine "spec/*spec.js": 333 specs, 0 failures, 2 pending.
• The benchmarks in benchmark/ exercise the parser and builder, not the validator, so I did not include perf numbers. The change only alters an index argument.
• lib/ and the changelog are left for the maintainers, per CONTRIBUTING.

[by-ae]

Checked this out locally (head a766423) and ran it against master:

• the new spec fails on master (66 specs, 1 failure in validator_spec.js) and the full suite passes on the branch (333 specs, 0 failures, 2 pending)
• XMLValidator.validate('<foo><?xml version="1.0"?></foo>') returns true on master and the InvalidXml error on the branch, same for <foo>bar<?xml?></foo>
• normal PIs in content still validate: <foo><?pi data?></foo>, <foo><?pi?>text</foo> and <foo><?xml-stylesheet href="a"?></foo> all stay true

One thing still slips through, both before and after this change: readPI only ends the target name on ? or a space (validator.js#L204), so a declaration that uses a newline or tab after xml is still accepted inside an element:

XMLValidator.validate('<foo><?xml\nversion="1.0"?></foo>')  // true
XMLValidator.validate('<foo><?xml\tversion="1.0"?></foo>')  // true

XML allows any of space, tab, CR or LF there (the S production), so treating \t, \n and \r like ' ' in that check would close the gap. Fine as a follow-up though, the index fix here is correct on its own.