SERVER-11149 2dsphere handle sparse like other indices

2 files changed, 40 insertions, 5 deletions

diff --git a/jstests/geo_s2sparse.js b/jstests/geo_s2sparse.js
index ee5d41ac940..df1b1eb19e6 100644
--- a/jstests/geo_s2sparse.js
+++ b/jstests/geo_s2sparse.js
@@ -2,6 +2,40 @@
 t = db.geo_s2sparse;
 t.drop();
 
+//
+// Sparse on
+//
+
+// Insert a doc. that is indexed
+pointA = { "type" : "Point", "coordinates": [ 40, 5 ] }
+t.insert( {geo : pointA , nonGeo: "pointA"})
+// Make a sparse index.
+t.ensureIndex({geo: "2dsphere", otherNonGeo: 1}, {sparse: 1});
+
+// Save the size of the index with one obj.
+var sizeWithOneIndexedObj = t.stats().indexSizes.geo_2dsphere;
+
+// Insert a bunch of data that won't be indexed.
+var N = 1000;
+for (var i = 0; i < N; ++i) {
+    // Missing both.
+    t.insert( {nonGeo: "pointA"})
+    // Missing geo.
+    t.insert( {geo: pointA})
+    // Missing nonGeo.
+    t.insert( {otherNonGeo: "pointA"})
+}
+
+// The size should be the same as we don't index no-geo data.
+var sizeAfter = t.stats().indexSizes.geo_2dsphere;
+assert.eq(sizeAfter, sizeWithOneIndexedObj);
+
+//
+// Sparse off
+//
+
+t.drop();
+
 // Insert a doc. that is indexed
 pointA = { "type" : "Point", "coordinates": [ 40, 5 ] }
 t.insert( {geo : pointA , nonGeo: "pointA"})
@@ -17,6 +51,7 @@ for (var i = 0; i < N; ++i) {
     t.insert( {nonGeo: "pointA"})
 }
 
-// The size should be the same as we don't index the missing data.
+// Since the index isn't sparse we have entries in the index for each insertion even though it's
+// missing the geo key.
 var sizeAfter = t.stats().indexSizes.geo_2dsphere;
-assert.eq(sizeAfter, sizeWithOneIndexedObj);
+assert.gt(sizeAfter, sizeWithOneIndexedObj);
diff --git a/src/mongo/db/index/s2_access_method.cpp b/src/mongo/db/index/s2_access_method.cpp
index ebab9df183c..64cfd4cef55 100644
--- a/src/mongo/db/index/s2_access_method.cpp
+++ b/src/mongo/db/index/s2_access_method.cpp
@@ -102,11 +102,11 @@ namespace mongo {
             // false means Don't expand the last array, duh.
             obj.getFieldsDotted(e.fieldName(), fieldElements, false);
 
+            // If we're sparse and we're missing any field, bail out.
+            if (_descriptor->isSparse() && fieldElements.empty()) { return; }
+
             BSONObjSet keysForThisField;
             if (IndexNames::GEO_2DSPHERE == e.valuestr()) {
-                // We can't ever return documents that don't have geometry so don't bother indexing
-                // them.
-                if (fieldElements.empty()) { return; }
                 getGeoKeys(obj, fieldElements, &keysForThisField);
             } else {
                 getLiteralKeys(fieldElements, &keysForThisField);