[LANG-1828] Fix OOM in StringUtils.leftPad/rightPad when size is Integer.MIN_VALUE

[dhruvaggarwal2000]

This issue is tracked as LANG-1828.

Repro:
size - str.length() underflows when size = Integer.MIN_VALUE, bypassing the pads <= 0 early return and causing an OOM allocation.

Fix: Short-circuiting on size <= str.length() before the subtraction — no behavior change for any valid input.

Methods affected:

• leftPad(String, int, char)
• leftPad(String, int, String)
• rightPad(String, int, char)
• rightPad(String, int, String)

Compatibility report (mvn package japicmp:cmp against 3.20.0)

org.apache.commons.lang3.StringUtils

• Binary-compatible
• Source-compatible
• Serialization-compatible

Status	Modifiers	Type	Name	Extends	JDK	Serialization	Compatibility Changes
Modified	public	Class	StringUtils	[Object]	JDK 8	![Not serializable]	![No changes]

Before you push a pull request, review this list:

• Read the contribution guidelines for this project.
• Read the ASF Generative Tooling Guidance if you use Artificial Intelligence (AI).
• AI used: Claude (Anthropic, claude-opus-4-7) via the Claude Code CLI, to draft this PR description. Per ASF guidance: Anthropic's terms place no restrictions inconsistent with the OSD; no third-party material is reproduced in the output.
• Run a successful build using the default Maven.
• 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.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• 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.

[garydgregory]

@dhruvaggarwal2000
Thank you for the PR. Please try to reduce the usual AI verbosity of code generation. I refactored the guard clauses and pushed to git master (instead of going round and round here to save time). You are credited in changes.xml. Closing.

[dhruvaggarwal2000]

Got it — trimmed the description. Noted for future PRs