SERVER-33092 Fix elemMatchProjection.js to always have monotonically increasing _ids.

(cherry picked from commit ab9fbc6a90c65d228dd15973aa6706563c086106)

Conflicts:
      jstests/core/elemMatchProjection.js

1 files changed, 37 insertions, 13 deletions

diff --git a/jstests/core/elemMatchProjection.js b/jstests/core/elemMatchProjection.js
index 4e80e8a296e..5060d8a6346 100644
--- a/jstests/core/elemMatchProjection.js
+++ b/jstests/core/elemMatchProjection.js
@@ -4,35 +4,59 @@ t.drop();
 
 date1 = new Date();
 
+// Generate monotonically increasing _id values. ObjectIds generated by the shell are not guaranteed
+// to be monotically increasing, and we will depend on the _id sort order later in the test.
+var currentId = 0;
+function nextId() {
+    return ++currentId;
+}
+
 // Insert various styles of arrays
 for (i = 0; i < 100; i++) {
-    t.insert({group: 1, x: [1, 2, 3, 4, 5]});
-    t.insert({group: 2, x: [{a: 1, b: 2}, {a: 2, c: 3}, {a: 1, d: 5}]});
+    t.insert({_id: nextId(), group: 1, x: [1, 2, 3, 4, 5]});
+    t.insert({_id: nextId(), group: 2, x: [{a: 1, b: 2}, {a: 2, c: 3}, {a: 1, d: 5}]});
     t.insert({
+        _id: nextId(),
         group: 3,
         x: [{a: 1, b: 2}, {a: 2, c: 3}, {a: 1, d: 5}],
         y: [{aa: 1, bb: 2}, {aa: 2, cc: 3}, {aa: 1, dd: 5}]
     });
-    t.insert({group: 3, x: [{a: 1, b: 3}, {a: -6, c: 3}]});
-    t.insert({group: 4, x: [{a: 1, b: 4}, {a: -6, c: 3}]});
-    t.insert({group: 5, x: [new Date(), 5, 10, 'string', new ObjectId(), 123.456]});
+    t.insert({_id: nextId(), group: 3, x: [{a: 1, b: 3}, {a: -6, c: 3}]});
+    t.insert({_id: nextId(), group: 4, x: [{a: 1, b: 4}, {a: -6, c: 3}]});
+    t.insert({_id: nextId(), group: 5, x: [new Date(), 5, 10, 'string', new ObjectId(), 123.456]});
     t.insert({
+        _id: nextId(),
         group: 6,
         x: [{a: 'string', b: date1}, {a: new ObjectId(), b: 1.2345}, {a: 'string2', b: date1}]
     });
-    t.insert({group: 7, x: [{y: [1, 2, 3, 4]}]});
-    t.insert({group: 8, x: [{y: [{a: 1, b: 2}, {a: 3, b: 4}]}]});
-    t.insert({group: 9, x: [{y: [{a: 1, b: 2}, {a: 3, b: 4}]}, {z: [{a: 1, b: 2}, {a: 3, b: 4}]}]});
-    t.insert({group: 10, x: [{a: 1, b: 2}, {a: 3, b: 4}], y: [{c: 1, d: 2}, {c: 3, d: 4}]});
-    t.insert({group: 10, x: [{a: 1, b: 2}, {a: 3, b: 4}], y: [{c: 1, d: 2}, {c: 3, d: 4}]});
+    t.insert({_id: nextId(), group: 7, x: [{y: [1, 2, 3, 4]}]});
+    t.insert({_id: nextId(), group: 8, x: [{y: [{a: 1, b: 2}, {a: 3, b: 4}]}]});
+    t.insert({
+        _id: nextId(),
+        group: 9,
+        x: [{y: [{a: 1, b: 2}, {a: 3, b: 4}]}, {z: [{a: 1, b: 2}, {a: 3, b: 4}]}]
+    });
+    t.insert({
+        _id: nextId(),
+        group: 10,
+        x: [{a: 1, b: 2}, {a: 3, b: 4}],
+        y: [{c: 1, d: 2}, {c: 3, d: 4}]
+    });
+    t.insert({
+        _id: nextId(),
+        group: 10,
+        x: [{a: 1, b: 2}, {a: 3, b: 4}],
+        y: [{c: 1, d: 2}, {c: 3, d: 4}]
+    });
     t.insert({
+        _id: nextId(),
         group: 11,
         x: [{a: 1, b: 2}, {a: 2, c: 3}, {a: 1, d: 5}],
         covered: [{aa: 1, bb: 2}, {aa: 2, cc: 3}, {aa: 1, dd: 5}]
     });
-    t.insert({group: 12, x: {y: [{a: 1, b: 1}, {a: 1, b: 2}]}});
-    t.insert({group: 13, x: [{a: 1, b: 1}, {a: 1, b: 2}]});
-    t.insert({group: 13, x: [{a: 1, b: 2}, {a: 1, b: 1}]});
+    t.insert({_id: nextId(), group: 12, x: {y: [{a: 1, b: 1}, {a: 1, b: 2}]}});
+    t.insert({_id: nextId(), group: 13, x: [{a: 1, b: 1}, {a: 1, b: 2}]});
+    t.insert({_id: nextId(), group: 13, x: [{a: 1, b: 2}, {a: 1, b: 1}]});
 }
 t.ensureIndex({
     group: 1,