StringUtils.chompLast: fix StringIndexOutOfBoundsException when sep longer than str

[elharo]

StringUtils.chompLast(String str, String sep) at line 857 computes str.substring(str.length() - sep.length()) without checking whether sep is longer than str. When sep.length() > str.length(), the start index is negative, throwing StringIndexOutOfBoundsException.

Fix: Added || sep.length() > str.length() to the existing guard, returning str unchanged when the separator is longer than the string (since it can't possibly end with that separator).

Fixes #400

[Copilot]

Pull request overview

Fixes StringUtils.chompLast(String str, String sep) to avoid StringIndexOutOfBoundsException when sep.length() > str.length() by returning str unchanged in that case (consistent with “can’t possibly end with sep”). This aligns with the reported behavior in Issue #400.

Changes:

• Added a guard in StringUtils.chompLast(str, sep) to return early when the separator is longer than the input string.
• Added a regression test covering chompLast("x", "ab").

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/main/java/org/apache/maven/shared/utils/StringUtils.java	Adds length guard to prevent negative substring start index when sep is longer than str.
src/test/java/org/apache/maven/shared/utils/StringUtilsTest.java	Adds a regression test to verify chompLast returns the original string when sep is longer.

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