[LUCENE-7719] UnifiedHighlighter doesn't handle some AutomatonQuery's with multi-byte chars

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 7.0
• Component/s: modules/highlighter
• Lucene Fields: New
• Assignee: David Smiley
• Reporter: David Smiley
• Created: 01/Mar/17 07:00
• Updated: 28/Aug/22 15:11
• Resolved: 17/Jun/17 03:01

Description

In MultiTermHighlighting, a CharacterRunAutomaton is being created that takes the result of AutomatonQuery.getAutomaton that in turn is byte oriented, not character oriented. For ASCII terms, this is safe but it's not for multi-byte characters. This is most likely going to rear it's head with a WildcardQuery, but due to special casing in MultiTermHighlighting, PrefixQuery isn't affected. Nonetheless it'd be nice to get a general fix in so that MultiTermHighlighting can remove special cases for PrefixQuery and TermRangeQuery (both subclass AutomatonQuery).

AFAICT, this bug was likely in the PostingsHighlighter since inception.

Issue Links

• relates to: LUCENE-7717 UnifiedHighlighter doesn't highlight PrefixQuery with multi-byte chars