Steps to replicate the issue:
- Use <gallery data-test="123">Test.png</gallery>
- Observe the DOM on the legacy parser to see it has data-test="123" on the <ul> element
- Switch to Parsoid
What happens?: Parsoid does not emit data-test="123" on the <ul> element
What should have happened instead?: Parsoid should have emitted the attribute.
Other information: Parsoid calls Sanitizer::attributesAllowedInternal to retrieve a list of allowed attributes (which cannot account for allowed data attributes) instead of calling Sanitizer::sanitizeTagAttrs that accounts for data attributes.