SERVER-13677 traverse through ALL when finding predicates inside elemMatch object

(cherry picked from commit 54bdb39ba62c25ef59221fcab866501c02a06047)

2 files changed, 36 insertions, 1 deletions

diff --git a/src/mongo/db/query/planner_access.cpp b/src/mongo/db/query/planner_access.cpp
index 0dc1913ec57..fc0fb1c2030 100644
--- a/src/mongo/db/query/planner_access.cpp
+++ b/src/mongo/db/query/planner_access.cpp
@@ -490,7 +490,7 @@ namespace mongo {
                 out->push_back(child);
             }
             else if (MatchExpression::AND == child->matchType() ||
-                     MatchExpression::ELEM_MATCH_OBJECT == child->matchType()) {
+                     Indexability::arrayUsesIndexOnChildren(child)) {
                 findElemMatchChildren(child, out);
             }
         }
diff --git a/src/mongo/db/query/query_planner_test.cpp b/src/mongo/db/query/query_planner_test.cpp
index 83092ddb49e..5523675d9c5 100644
--- a/src/mongo/db/query/query_planner_test.cpp
+++ b/src/mongo/db/query/query_planner_test.cpp
@@ -1230,6 +1230,41 @@ namespace {
                                 "node: {ixscan: {filter: null, pattern: {'foo.b': 1}}}}}");*/
     }
 
+    // SERVER-13677
+    TEST_F(QueryPlannerTest, ElemMatchWithAllElemMatchChild) {
+        addIndex(BSON("a.b.c.d" << 1));
+        runQuery(fromjson("{z: 1, 'a.b': {$elemMatch: {c: {$all: [{$elemMatch: {d: 0}}]}}}}"));
+
+        assertNumSolutions(2U);
+        assertSolutionExists("{cscan: {dir: 1}}");
+        assertSolutionExists("{fetch: {node: {ixscan: {pattern: {'a.b.c.d': 1}}}}}");
+    }
+
+    // SERVER-13677
+    TEST_F(QueryPlannerTest, ElemMatchWithAllElemMatchChild2) {
+        // true means multikey
+        addIndex(BSON("a.b.c.d" << 1), true);
+        runQuery(fromjson("{'a.b': {$elemMatch: {c: {$all: "
+                            "[{$elemMatch: {d: {$gt: 1, $lt: 3}}}]}}}}"));
+
+        assertNumSolutions(2U);
+        assertSolutionExists("{cscan: {dir: 1}}");
+        assertSolutionExists("{fetch: {node: {ixscan: {pattern: {'a.b.c.d': 1}, "
+                                "bounds: {'a.b.c.d': [[-Infinity,3,true,false]]}}}}}");
+    }
+
+    // SERVER-13677
+    TEST_F(QueryPlannerTest, ElemMatchWithAllChild) {
+        // true means multikey
+        addIndex(BSON("a.b.c" << 1), true);
+        runQuery(fromjson("{z: 1, 'a.b': {$elemMatch: {c: {$all: [4, 5, 6]}}}}"));
+
+        assertNumSolutions(2U);
+        assertSolutionExists("{cscan: {dir: 1}}");
+        assertSolutionExists("{fetch: {node: {ixscan: {pattern: {'a.b.c': 1}, "
+                                "bounds: {'a.b.c': [[4,4,true,true]]}}}}}");
+    }
+
     TEST_F(QueryPlannerTest, ElemMatchValueMatch) {
         addIndex(BSON("foo" << 1));
         addIndex(BSON("foo" << 1 << "bar" << 1));