fix(parser): pass modifier to ExceptOp/MinusOp constructors (#2419)

[queelius]

Summary

• Fix EXCEPT ALL/DISTINCT and MINUS ALL/DISTINCT modifiers being silently dropped during parsing
• Reset the modifier variable between set-operation loop iterations to prevent modifier leaking from one operator to the next

Problem

The grammar in JSqlParserCC.jjt captures the set operation modifier via SetOperationModifier() but constructs ExceptOp and MinusOp with their no-arg constructors (which default to empty string), discarding the captured modifier. UnionOp and IntersectOp correctly receive modifier as a constructor argument.

// CORRECT: modifier passed to constructor
<K_UNION> [ modifier=SetOperationModifier() ] { UnionOp union = new UnionOp(modifier); ... }
<K_INTERSECT> [ modifier=SetOperationModifier() ] { IntersectOp intersect = new IntersectOp(modifier); ... }

// BUG: modifier NOT passed to constructor
<K_MINUS> [ modifier=SetOperationModifier() ] { MinusOp minus = new MinusOp(); ... }
<K_EXCEPT> [ modifier=SetOperationModifier() ] { ExceptOp except = new ExceptOp(); ... }

Additionally, the modifier variable was not reset between iterations of the (LOOKAHEAD(2) ...)+ loop, so a UNION ALL ... EXCEPT would incorrectly leak the ALL modifier to the EXCEPT.

Fix

1. Pass modifier to MinusOp(modifier) and ExceptOp(modifier) constructors
2. Add { modifier = null; } at the start of each loop iteration

Test plan

• testExceptAllRoundTrip - verifies EXCEPT ALL round-trips correctly
• testExceptDistinctRoundTrip - verifies EXCEPT DISTINCT round-trips correctly
• testMinusAllRoundTrip - verifies MINUS ALL round-trips correctly
• testMinusDistinctRoundTrip - verifies MINUS DISTINCT round-trips correctly
• testModifierDoesNotLeakFromUnionAllToExcept - verifies modifier doesn't leak across operators
• testModifierDoesNotLeakFromIntersectAllToUnion - verifies modifier doesn't leak across operators
• testMixedModifiersPreserved - verifies mixed modifiers in chained set ops
• testExceptAllSetOperationObject / testMinusAllSetOperationObject - verifies SetOperation state
• Full test suite passes (4671+ tests, 0 failures)

Fixes #2419

🤖 Generated with Claude Code

[manticore-projects]

Thank you very much for finding and fixing this.
I would merge as soon as the CI/QA passes.

Since you are using a LLM assistant: please use Parametrized Unit Tests where possible. And run './gradlew spotlessApply' to fix all violations. Thanks!

[Copilot]

Pull request overview

This PR fixes parsing/deparsing fidelity for set-operation modifiers by ensuring ALL/DISTINCT captured by the grammar are preserved for EXCEPT and MINUS, and by preventing modifier state from leaking across chained set operations.

Changes:

• Pass the parsed modifier into MinusOp(modifier) and ExceptOp(modifier) constructors.
• Reset modifier at the start of each set-operation loop iteration to prevent modifier leakage.
• Add regression tests covering round-trip behavior and object state for EXCEPT/MINUS modifiers, plus leak-prevention cases.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt	Ensures EXCEPT/MINUS retain ALL/DISTINCT modifiers and avoids modifier leakage between operations.
src/test/java/net/sf/jsqlparser/statement/select/SetOperationModifierTest.java	Adds regression coverage for modifier preservation and leakage prevention across chained set operations.

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[Copilot]

The Javadoc references issue #2080, but this PR (and the described regression) is for #2419. Please update the link so future readers can trace the correct bug report.

Suggested change

	* @see <a href="https://github.com/JSQLParser/JSqlParser/issues/2080">#2080</a>
	* @see <a href="https://github.com/JSQLParser/JSqlParser/issues/2419">#2419</a>

[queelius]

Converted to parameterized tests and ran spotlessApply. Thanks for the quick feedback.