SERVER-23436 ProjectionNode::getSort propagates sort from children.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/mongo/db/query/query_solution.h b/src/mongo/db/query/query_solution.h
index 72feaca50b9..f64e5d263dc 100644
--- a/src/mongo/db/query/query_solution.h
+++ b/src/mongo/db/query/query_solution.h
@@ -496,7 +496,7 @@ struct ProjectionNode : public QuerySolutionNode {
         SIMPLE_DOC,
     };
 
-    ProjectionNode() : fullExpression(NULL), projType(DEFAULT) {}
+    ProjectionNode(ParsedProjection proj) : fullExpression(NULL), projType(DEFAULT), parsed(proj) {}
 
     virtual ~ProjectionNode() {}
 
@@ -504,6 +504,8 @@ struct ProjectionNode : public QuerySolutionNode {
         return STAGE_PROJECTION;
     }
 
+    virtual void computeProperties();
+
     virtual void appendToString(mongoutils::str::stream* ss, int indent) const;
 
     /**
@@ -532,8 +534,6 @@ struct ProjectionNode : public QuerySolutionNode {
     }
 
     const BSONObjSet& getSort() const {
-        // TODO: If we're applying a projection that maintains sort order, the prefix of the
-        // sort order we project is the sort order.
         return _sorts;
     }
 
@@ -552,6 +552,8 @@ struct ProjectionNode : public QuerySolutionNode {
     // What implementation of the projection algorithm should we use?
     ProjectionType projType;
 
+    ParsedProjection parsed;
+
     // Only meaningful if projType == COVERED_ONE_INDEX.  This is the key pattern of the index
     // supplying our covered data.  We can pre-compute which fields to include and cache that
     // data for later if we know we only have one index.