Lucene cannot parse terms ending with a backslash

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 6.2.5 CE GA6, 6.2.10 EE GA1, 6.2.X EE
• Fix Version/s: 6.2.X EE
• Component/s: Search Infrastructure, Search Infrastructure > Lucene Impl
• Labels:
  • 6.2.x-only
  • ee-ts
  • liferay-fixpack-portal-94-6210
• Branch Version/s:
  6.2.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal-ee/pull/12593
• Bug Type: Regression Bug

Reproduction steps:

1. In Control Panel -> Server Administration -> Log Levels, add com.liferay.portal.search.lucene.LuceneHelperImpl to WARN
2. Add a search portlet to a page
3. Search for anything with a backslash at the end, e.g. "test\"

Result: The following warning occurs in the log:

10:35:15,412 WARN  [ajp-apr-8010-exec-41][LuceneHelperImpl:269] org.apache.lucene.queryParser.ParseException: Cannot parse '\': Lexical error at line 1, column 2.  Encountered: <EOF> after : ""
org.apache.lucene.queryParser.ParseException: Cannot parse '\': Lexical error at line 1, column 2.  Encountered: <EOF> after : ""
        at org.apache.lucene.queryParser.QueryParser.parse(QueryParser.java:216)
        at com.liferay.portal.search.lucene.LuceneHelperImpl.addTerm(LuceneHelperImpl.java:251)
        at com.liferay.portal.search.lucene.LuceneHelperImpl.addTerm(LuceneHelperImpl.java:218)
        at com.liferay.portal.search.lucene.LuceneHelperUtil.addTerm(LuceneHelperUtil.java:268)
        at com.liferay.portal.search.lucene.LuceneHelperUtil.addTerm(LuceneHelperUtil.java:262)
        at com.liferay.portal.search.lucene.BooleanQueryImpl.addTerm(BooleanQueryImpl.java:270)

Expected: No warnings should appear.