SERVER-38601 Add regression test for SERVER-35455

1 files changed, 41 insertions, 0 deletions

diff --git a/jstests/core/contained_or_with_nested_or.js b/jstests/core/contained_or_with_nested_or.js
new file mode 100644
index 00000000000..b0add6fdeb1
--- /dev/null
+++ b/jstests/core/contained_or_with_nested_or.js
@@ -0,0 +1,41 @@
+// This test was designed to reproduce a memory leak that was fixed by SERVER-35455.
+(function() {
+    "use strict";
+
+    const coll = db.contained_or_with_nested_or;
+    coll.drop();
+    assert.commandWorked(coll.insert([
+        // Should not match the query:
+        {_id: 0, active: false, loc: "USA", agency: "FBI", vip: false},
+        {_id: 1, active: false, loc: "RUS", agency: "OTHER", vip: true},
+        {_id: 2, active: true, loc: "RUS", agency: "OTHER", vip: false},
+        {_id: 3, active: true, loc: "USA", agency: "OTHER", vip: false},
+        {_id: 4, active: true, loc: "UK", agency: "OTHER", vip: false},
+        {_id: 5, active: true, loc: "UK", agency: "OTHER", vip: true},
+        {_id: 6, active: true},
+        // Should match the query:
+        {_id: 7, active: true, loc: "USA", agency: "FBI", vip: false},
+        {_id: 8, active: true, loc: "USA", agency: "CIA", vip: true},
+        {_id: 9, active: true, loc: "RUS", agency: "OTHER", vip: true},
+        {_id: 10, active: true, loc: "RUS", agency: "KGB"},
+    ]));
+    assert.commandWorked(coll.createIndexes([{loc: 1}, {agency: 1}, {vip: 1}]));
+
+    // The following query reproduced the memory leak described in SERVER-38601. To catch a
+    // regression, we would only expect this test to fail on ASAN variants. Before SERVER-35455 we
+    // would construct a plan for one clause of the $or, then realize that the other clause could
+    // not be indexed and discard the plan for the first clause in a way that leaks memory.
+    const results = coll.find({
+                            active: true,
+                            $or: [
+                                {loc: "USA", $or: [{agency: "FBI"}, {vip: true}]},
+                                {loc: "RUS", $or: [{agency: "KGB"}, {vip: true}]}
+                            ]
+                        })
+                        .toArray();
+
+    // Just assert on the matching _ids. We avoid adding a sort to the query above to avoid
+    // restricting the plans the query planner can consider.
+    const matchingIds = results.map(result => result._id);
+    assert.setEq(new Set(matchingIds), new Set([7, 8, 9, 10]));
+}());