1 files changed, 90 insertions, 0 deletions
diff --git a/jstests/core/query/cursor/tailable_skip_limit.js b/jstests/core/query/cursor/tailable_skip_limit.js
new file mode 100644
index 00000000000..215378a5870
--- /dev/null
+++ b/jstests/core/query/cursor/tailable_skip_limit.js
@@ -0,0 +1,90 @@
+// @tags: [
+//   requires_capped,
+//   requires_getmore,
+//   # This test has statements that do not support non-local read concern.
+//   does_not_support_causal_consistency,
+// ]
+
+// Test that tailable cursors work correctly with skip and limit.
+(function() {
+"use strict";
+
+// Setup the capped collection.
+var collname = "jstests_tailable_skip_limit";
+var t = db[collname];
+t.drop();
+assert.commandWorked(db.createCollection(collname, {capped: true, size: 1024}));
+
+assert.commandWorked(t.insert({_id: 1}));
+assert.commandWorked(t.insert({_id: 2}));
+
+// Non-tailable with skip
+var cursor = t.find().skip(1);
+assert.eq(2, cursor.next()["_id"]);
+assert(!cursor.hasNext());
+assert.commandWorked(t.insert({_id: 3}));
+assert(!cursor.hasNext());
+
+// Non-tailable with limit
+var cursor = t.find().limit(100);
+for (var i = 1; i <= 3; i++) {
+    assert.eq(i, cursor.next()["_id"]);
+}
+assert(!cursor.hasNext());
+assert.commandWorked(t.insert({_id: 4}));
+assert(!cursor.hasNext());
+
+// Non-tailable with negative limit
+var cursor = t.find().limit(-100);
+for (var i = 1; i <= 4; i++) {
+    assert.eq(i, cursor.next()["_id"]);
+}
+assert(!cursor.hasNext());
+assert.commandWorked(t.insert({_id: 5}));
+assert(!cursor.hasNext());
+
+// Tailable with skip
+cursor = t.find().addOption(2).skip(4);
+assert.eq(5, cursor.next()["_id"]);
+assert(!cursor.hasNext());
+assert.commandWorked(t.insert({_id: 6}));
+assert(cursor.hasNext());
+assert.eq(6, cursor.next()["_id"]);
+
+// Tailable with limit
+var cursor = t.find().addOption(2).limit(100);
+for (var i = 1; i <= 6; i++) {
+    assert.eq(i, cursor.next()["_id"]);
+}
+assert(!cursor.hasNext());
+assert.commandWorked(t.insert({_id: 7}));
+assert(cursor.hasNext());
+assert.eq(7, cursor.next()["_id"]);
+
+// Tailable with negative limit is an error.
+assert.throws(function() {
+    t.find().addOption(2).limit(-100).next();
+});
+assert.throws(function() {
+    t.find().addOption(2).limit(-1).itcount();
+});
+
+// A limit of 1 with the tailable option is allowed.
+assert.eq(1, t.find().addOption(2).limit(1).itcount());
+
+// Tests that a tailable cursor over an empty capped collection produces a dead cursor, intended
+// to be run on both mongod and mongos. For SERVER-20720.
+t.drop();
+assert.commandWorked(db.createCollection(t.getName(), {capped: true, size: 1024}));
+
+var cmdRes = db.runCommand({find: t.getName(), tailable: true});
+assert.commandWorked(cmdRes);
+assert.eq(cmdRes.cursor.id, NumberLong(0));
+assert.eq(cmdRes.cursor.ns, t.getFullName());
+assert.eq(cmdRes.cursor.firstBatch.length, 0);
+
+// Test that the cursor works in the shell.
+assert.eq(t.find().addOption(2).itcount(), 0);
+assert.commandWorked(t.insert({a: 1}));
+assert.eq(t.find().addOption(2).itcount(), 1);
+})();