apache / apache/lucene

Avoid throwing StackOverflowError when creating RegExp [LUCENE-10474]

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legacy-jira-priority:Minor module:core/other type:enhancement
Dominant language
Java
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Merged PRs (30d)
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Description

Creating a regular expression using Lucene's RegExp class can easily result in a StackOverflowError being thrown, for example when the input is larger than the maximum stack depth. Throwing a StackOverflowError isn't something a user would expect, and it isn't documented either. StackOverflowError is a user-unfriendly exception as it does not convey any intent that the user has done something wrong, but suggests a bug in the implementation.

I would like Lucene to follow the [approach taken by the JDK](https://github.com/openjdk/jdk/blob/cab4ff64541393a974ea91e35167668ef0036804/src/java.base/share/classes/java/util/regex/Pattern.java#L1441) and throw an IllegalArgumentException instead to clearly mark this as an input that the implementation can't handle.

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Migrated from [LUCENE-10474](https://issues.apache.org/jira/browse/LUCENE-10474) by Yannick Welsch (@ywelsch), updated Mar 21 2022
Pull requests: https://github.com/apache/lucene/pull/752, https://github.com/apache/lucene/pull/752

Contributor guide

Open the contributing guide

Research direction

Start with Lucene's RegExp class and compare its handling of oversized regular expressions with the linked JDK Pattern.java approach. Done means inputs that currently cause StackOverflowError instead produce IllegalArgumentException, with the existing pull request and related tests checked for expected behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
search
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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