SERVER-43816 Push $text and $meta:"textScore" sort into the PlanStage layer.

This change involves unifying the behavior of find and
agg for validation of $meta:"textScore". In particular, find
operations no longer require a "textScore" $meta projection
in order to specify a "textScore" $meta sort. This brings
find into alignment with agg, which never had such a
restriction. It is also now legal for a find command to
sort on the field overridden by a $meta:"textScore" projection
without specifying the $meta operator in the sort pattern.

In addition:
 - Tightens validation around uses of "textScore" $meta
 projections for queries that do not specify a $text
 predicate.
 - Fixes a bug in which $natural sort/hint were not
 correctly validated.

1 files changed, 0 insertions, 9 deletions

diff --git a/src/mongo/db/query/query_request.h b/src/mongo/db/query/query_request.h
index 1457480b3dd..ae2ed26036b 100644
--- a/src/mongo/db/query/query_request.h
+++ b/src/mongo/db/query/query_request.h
@@ -109,15 +109,6 @@ public:
      */
     static bool isTextScoreMeta(BSONElement elt);
 
-    /**
-     * Helper function to validate a sort object.
-     * Returns true if each element satisfies one of:
-     * 1. a number with value 1
-     * 2. a number with value -1
-     * 3. isTextScoreMeta
-     */
-    static bool isValidSortOrder(const BSONObj& sortObj);
-
     // Read preference is attached to commands in "wrapped" form, e.g.
     //   { $query: { <cmd>: ... } , <kWrappedReadPrefField>: { ... } }
     //