Regular expression failure for certain strings

[wenleix]

presto> select REGEXP_EXTRACT('Baby K', 'by ([A-Z].*)\b[a-z]');


Query 20170809_223707_70717_ucc54 failed: 6
java.lang.ArrayIndexOutOfBoundsException: 6
        at io.airlift.jcodings.MultiByteEncoding.safeLengthForUptoFour(MultiByteEncoding.java:64)
        at io.airlift.jcodings.specific.NonStrictUTF8Encoding.length(NonStrictUTF8Encoding.java:30)
        at io.airlift.jcodings.specific.BaseUTF8Encoding.mbcToCode(BaseUTF8Encoding.java:91)
        at io.airlift.jcodings.specific.NonStrictUTF8Encoding.mbcToCode(NonStrictUTF8Encoding.java:22)
        at io.airlift.jcodings.Encoding.isMbcWord(Encoding.java:469)
        at io.airlift.joni.ByteCodeMachine.opWordBound(ByteCodeMachine.java:1063)
        at io.airlift.joni.ByteCodeMachine.matchAt(ByteCodeMachine.java:239)
        at io.airlift.joni.Matcher.matchCheck(Matcher.java:304)
        at io.airlift.joni.Matcher.searchInterruptible(Matcher.java:457)
        at io.airlift.joni.Matcher.search(Matcher.java:318)
        at com.facebook.presto.operator.scalar.JoniRegexpFunctions.regexpExtract(JoniRegexpFunctions.java:256)
        at com.facebook.presto.operator.scalar.JoniRegexpFunctions.regexpExtract(JoniRegexpFunctions.java:242)
        at com.facebook.presto.$gen.PageProjection_20170809_223707_70717_ucc54_0_71_270090.project(Unknown Source)
        at com.facebook.presto.$gen.PageProjection_20170809_223707_70717_ucc54_0_71_270090.project(Unknown Source)
        at com.facebook.presto.operator.project.PageProcessor$PositionsPageProcessorIterator.processBatch(PageProcessor.java:186)
        at com.facebook.presto.operator.project.PageProcessor$PositionsPageProcessorIterator.computeNext(PageProcessor.java:132)
        at com.facebook.presto.operator.project.PageProcessor$PositionsPageProcessorIterator.computeNext(PageProcessor.java:106)
        at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:145)
        at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:140)
        at com.facebook.presto.operator.project.PageProcessorOutput.hasNext(PageProcessorOutput.java:51)
        at com.facebook.presto.operator.FilterAndProjectOperator.isFinished(FilterAndProjectOperator.java:71)
        at com.facebook.presto.operator.Driver.processInternal(Driver.java:297)
        at com.facebook.presto.operator.Driver.lambda$processFor$6(Driver.java:234)
        at com.facebook.presto.operator.Driver.tryWithLock(Driver.java:538)
        at com.facebook.presto.operator.Driver.processFor(Driver.java:229)
        at com.facebook.presto.execution.SqlTaskExecution$DriverSplitRunner.processFor(SqlTaskExecution.java:623)
        at com.facebook.presto.execution.executor.PrioritizedSplitRunner.process(PrioritizedSplitRunner.java:163)
        at com.facebook.presto.execution.executor.LegacyPrioritizedSplitRunner.process(LegacyPrioritizedSplitRunner.java:23)
        at com.facebook.presto.execution.executor.TaskExecutor$TaskRunner.run(TaskExecutor.java:483)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:748)

[satybald]

Looks like this bug is caused by regex library that presto is using airlift/joni. There's already issue opened by @haozhun
jruby/joni#28

[haozhun]

This was fixed in joni 2.1.7. Latest is joni 2.1.13. We are currently on joni 2.1.5.

@electrum How do we update given we have a fork?

[lopex]

Is there a reason you're using NonStrictUTF8Encoding ? It's been introduced as a non validating version for old ruby regexp engine compatibility. We're going to remove it from jruby/joni repo as it's no longer supported.

[haozhun]

@lopex Thank you for your attention. We are on non-strict because of jruby/joni#17

[lopex]

@haozhun ah totally forgot about that one.

[electrum]

Fixed in trinodb/trino#350