1 files changed, 40 insertions, 0 deletions
diff --git a/jstests/core/query/exists/exists9.js b/jstests/core/query/exists/exists9.js
new file mode 100644
index 00000000000..c187bb3a101
--- /dev/null
+++ b/jstests/core/query/exists/exists9.js
@@ -0,0 +1,40 @@
+// SERVER-393 Test exists with various empty array and empty object cases.
+
+t = db.jstests_exists9;
+t.drop();
+
+// Check existence of missing nested field.
+t.save({a: {}});
+assert.eq(1, t.count({'a.b': {$exists: false}}));
+assert.eq(0, t.count({'a.b': {$exists: true}}));
+
+// With index.
+t.createIndex({'a.b': 1});
+assert.eq(1, t.find({'a.b': {$exists: false}}).hint({'a.b': 1}).itcount());
+assert.eq(0, t.find({'a.b': {$exists: true}}).hint({'a.b': 1}).itcount());
+
+t.drop();
+
+// Check that an empty array 'exists'.
+t.save({});
+t.save({a: []});
+assert.eq(1, t.count({a: {$exists: true}}));
+assert.eq(1, t.count({a: {$exists: false}}));
+
+// With index.
+t.createIndex({a: 1});
+assert.eq(1, t.find({a: {$exists: true}}).hint({a: 1}).itcount());
+assert.eq(1, t.find({a: {$exists: false}}).hint({a: 1}).itcount());
+
+t.drop();
+
+// Check that an indexed field within an empty array does not exist.
+t.save({a: {'0': 1}});
+t.save({a: []});
+assert.eq(1, t.count({'a.0': {$exists: true}}));
+assert.eq(1, t.count({'a.0': {$exists: false}}));
+
+// With index.
+t.createIndex({'a.0': 1});
+assert.eq(1, t.find({'a.0': {$exists: true}}).hint({'a.0': 1}).itcount());
+assert.eq(1, t.find({'a.0': {$exists: false}}).hint({'a.0': 1}).itcount());