Hi,

Query:
contains("aaa","ab", 'http://www.w3.org/2005/xpath-functions/collation/html-ascii-case-insensitive')

Improper use? Potential bug? Your feedback is welcome:
Contact: basex-talk@mailman.uni-konstanz.de
Version: BaseX 8.4 beta 1814d39
Java: Oracle Corporation, 1.8.0_45
OS: Windows 8.1, amd64
Stack Trace:
java.lang.StringIndexOutOfBoundsException: String index out of range: 3
    at java.lang.String.charAt(Unknown Source)
    at org.basex.query.util.collation.NoCaseCollation.indexOf(NoCaseCollation.java:35)
    at org.basex.query.util.collation.Collation.contains(Collation.java:123)
    at org.basex.query.func.fn.FnContains.item(FnContains.java:20)
    at org.basex.query.func.StandardFunc.optimize(StandardFunc.java:83)
    at org.basex.query.func.StandardFunc.compile(StandardFunc.java:76)
    at org.basex.query.MainModule.compile(MainModule.java:74)
    at org.basex.query.QueryCompiler.compile(QueryCompiler.java:113)
    at org.basex.query.QueryCompiler.compile(QueryCompiler.java:104)
    at org.basex.query.QueryContext.analyze(QueryContext.java:332)
    at org.basex.query.QueryContext.compile(QueryContext.java:318)
    at org.basex.query.QueryProcessor.compile(QueryProcessor.java:70)
    at org.basex.core.cmd.AQuery.query(AQuery.java:76)
    at org.basex.core.cmd.XQuery.run(XQuery.java:22)
    at org.basex.core.Command.run(Command.java:398)
    at org.basex.core.Command.execute(Command.java:100)
    at org.basex.gui.GUI.exec(GUI.java:469)
    at org.basex.gui.GUI.access$4(GUI.java:422)
    at org.basex.gui.GUI$7.run(GUI.java:411)