db.c.insertMany([{_id: 1, a: [1]}, {_id: 2, a: []}, {_id: 3, a: {b: 1}}, {_id: 4, a: [{b: 2}]},
                 {_id: 5, a: 5}, {_id: 6, a: [{c: 1}]}, {_id: 7, a: ["x", 2]}]);
db.c.aggregate([{$match: {"a.b": PREDICATE}}, {$project: {_id: 1}}]);

/**
 * SBE ignores internalQueryLegacyDottedPathNullSemantics for MinKey/MaxKey comparisons on a
 * dotted path that crosses arrays: SBE returns the same documents under both settings, and
 * differs from the classic engine under each. Comparisons against null agree in both engines.
 */
const conn = MongoRunner.runMongod({setParameter: {internalQueryDisablePlanCache: true}});
const db = conn.getDB(jsTestName());
assert.commandWorked(db.c.insertMany([
    {_id: 1, a: [1]},
    {_id: 2, a: []},
    {_id: 3, a: {b: 1}},
    {_id: 4, a: [{b: 2}]},
    {_id: 5, a: 5},
    {_id: 6, a: [{c: 1}]},
    {_id: 7, a: ["x", 2]},
]));
const ids = (docs) => docs.map((d) => d._id).sort();

function run(pred, engine, legacy) {
    assert.commandWorked(db.adminCommand({
        setParameter: 1,
        internalQueryFrameworkControl: engine,
        internalQueryLegacyDottedPathNullSemantics: legacy,
    }));
    const pipeline = [{$match: {"a.b": pred}}, {$project: {_id: 1}}];
    const usedSbe = tojson(db.c.explain().aggregate(pipeline)).includes("slotBasedPlan");
    assert.eq(usedSbe, engine === "trySbeEngine", "engine setting did not take effect");
    const got = ids(db.c.aggregate(pipeline).toArray());
    jsTest.log.info("run", {pred, engine, legacy, got});
    return got;
}

// Controls: null comparisons agree between the engines under both settings.
for (const legacy of [true, false]) {
    assert.eq(run({$gte: null}, "trySbeEngine", legacy), run({$gte: null}, "forceClassicEngine", legacy),
              "$gte null, legacy=" + legacy);
}
// Per SERVER-131544, {field: {$gte: MinKey}} matches every document, no exceptions.
assert.eq(run({$gte: MinKey}, "forceClassicEngine", false), [1, 2, 3, 4, 5, 6, 7], "classic, non-legacy");

// Bug 1, default (legacy) setting. Fails at the local build (2026-09-17): SBE also returns 1 and 7.
assert.eq(run({$gte: MinKey}, "trySbeEngine", true), run({$gte: MinKey}, "forceClassicEngine", true),
          "$gte MinKey, legacy");
// Bug 2, non-legacy setting: SBE drops _id 2 (a: []).
assert.eq(run({$gte: MinKey}, "trySbeEngine", false), run({$gte: MinKey}, "forceClassicEngine", false),
          "$gte MinKey, non-legacy");
MongoRunner.stopMongod(conn);