alhudz opened a new pull request, #1707:
URL: https://github.com/apache/commons-lang/pull/1707
Repro: `StringUtils.substringAfter("a" + new
String(Character.toChars(0x1F600)) + "b", 0x1F600)` returns `"\uDE00b"` (a
dangling low surrogate) instead of `"b"`; `substringAfterLast(prefix + grin,
0x1F600)` returns `"\uDE00"` instead of `""`.
Cause: the code-point overloads locate `find` with `indexOf`/`lastIndexOf`,
which return the index of the high surrogate for a supplementary code point,
then step over the match by a fixed `+ 1`. `substringAfterLast` also tests its
terminal case with `pos == length() - 1`, so when the supplementary `find` is
the last code point the guard never fires.
Fix: advance by `Character.charCount(find)` and test the terminal guard
against `length() - charCount`. BMP code points keep `charCount == 1` so
existing behaviour is unchanged, and `substringBefore(String, int)` already
slices at `pos` so it needs no change.
- [x] Read the [contribution guidelines](CONTRIBUTING.md) for this project.
- [ ] Read the [ASF Generative Tooling
Guidance](https://www.apache.org/legal/generative-tooling.html) if you use
Artificial Intelligence (AI).
- [ ] I used AI to create any part of, or all of, this pull request. Which
AI tool was used to create this pull request, and to what extent did it
contribute?
- [ ] Run a successful build using the default
[Maven](https://maven.apache.org/) goal with `mvn`; that's `mvn` on the command
line by itself.
- [x] Write unit tests that match behavioral changes, where the tests fail
if the changes to the runtime are not applied. This may not always be possible,
but it is a best practice.
- [x] Write a pull request description that is detailed enough to understand
what the pull request does, how, and why.
- [x] Each commit in the pull request should have a meaningful subject line
and body. Note that a maintainer may squash commits during the merge process.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
