Copy the Option before applying property values in handleProperties

[farkhalit]

DefaultParser.handleProperties calls processValue on the Option instance owned by the caller's Options rather than on a copy, so a value that arrives through the defaults Properties is written into the shared Option and stays there after the parse. Reuse that same Options for a second parse and the isValuesEmpty guard silently serves the first parse's value instead of the second one's, the value remains readable through options.getOption(...), and two threads parsing at once write the same values list. Parser.processProperties has the same write-through and also puts the shared Option on the CommandLine, so a later parse rewrites what an earlier CommandLine returns.

Both property paths now clone before storing the value, which is what the argv paths already do in handleOption and processArgs. The new test in AbstractParserTestCase fails for DefaultParser, BasicParser, GnuParser and PosixParser without the change.

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[Copilot]

Pull request overview

Note

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Fixes property-based parsing so that option values from Properties are applied to a cloned Option rather than mutating the caller-owned Options, preventing value “write-through” across parses and threads.

Changes:

• Clone Option instances in both property-processing paths before applying processValue() / adding to CommandLine.
• Add a regression test ensuring reusing the same Options across parses doesn’t leak values into earlier CommandLines or into Options.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/test/java/org/apache/commons/cli/AbstractParserTestCase.java	Adds regression test covering Options reuse across property-based parses.
src/main/java/org/apache/commons/cli/Parser.java	Clones options in processProperties before setting values / adding to CommandLine.
src/main/java/org/apache/commons/cli/DefaultParser.java	Clones options in handleProperties before setting values / passing to handleOption.

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[farkhalit]

Done here too, same restructure: the continue happens first so no clone is made for a skipped flag.

[farkhalit]

Good point, fixed. The no-arg skip check now runs against opt before the clone, so a flag whose value isn't yes/true/1 never allocates a copy.

[garydgregory]

@farkhalit
Please review the Copilot comments.

[farkhalit]

Reviewed both Copilot notes, they're fair. Pushed a commit that moves the no-arg skip check ahead of the clone in both paths, so a flag whose property value isn't yes/true/1 no longer allocates a copy. Behavior is unchanged and the parser tests stay green.