SERVER-25535 Remove injectExpressionContext().

These methods were formally used to propagate a new ExpressionContext to
stages, accumulators, or expressions which potentially needed to
comparisons. Originally, this was necessary since Pipeline parsing
happened outside of the collection lock and thus could not determine if
there was a default collation on the collection. This meant that the
collation could change after parsing and any operators that might
compare strings would need to know about it.

We have since moved parsing within the lock, so the collation can be
known at parse time and the ExpressionContext should not change. This
patch requires an ExpressionContext at construction time, and disallows
changing the collation on an ExpressionContext.

1 files changed, 6 insertions, 3 deletions

diff --git a/src/mongo/db/pipeline/parsed_exclusion_projection.h b/src/mongo/db/pipeline/parsed_exclusion_projection.h
index ea7b25ac33f..d0988d2d2cb 100644
--- a/src/mongo/db/pipeline/parsed_exclusion_projection.h
+++ b/src/mongo/db/pipeline/parsed_exclusion_projection.h
@@ -108,8 +108,8 @@ public:
     /**
      * Parses the projection specification given by 'spec', populating internal data structures.
      */
-    void parse(const BSONObj& spec) final {
-        parse(spec, _root.get(), 0);
+    void parse(const boost::intrusive_ptr<ExpressionContext>& expCtx, const BSONObj& spec) final {
+        parse(expCtx, spec, _root.get(), 0);
     }
 
     /**
@@ -134,7 +134,10 @@ private:
      * Traverses 'spec' and parses each field. Adds any excluded fields at this level to 'node',
      * and recurses on any sub-objects.
      */
-    void parse(const BSONObj& spec, ExclusionNode* node, size_t depth);
+    void parse(const boost::intrusive_ptr<ExpressionContext>& expCtx,
+               const BSONObj& spec,
+               ExclusionNode* node,
+               size_t depth);
 
 
     // The ExclusionNode tree does most of the execution work once constructed.