1 files changed, 7 insertions, 10 deletions
diff --git a/src/mongo/db/pipeline/expression_js_emit.cpp b/src/mongo/db/pipeline/expression_js_emit.cpp
index dd43f587016..d19a9c53191 100644
--- a/src/mongo/db/pipeline/expression_js_emit.cpp
+++ b/src/mongo/db/pipeline/expression_js_emit.cpp
@@ -130,10 +130,10 @@ boost::intrusive_ptr<Expression> ExpressionInternalJsEmit::parse(ExpressionConte
     return new ExpressionInternalJsEmit(expCtx, std::move(thisRef), std::move(funcSourceString));
 }
 
-Value ExpressionInternalJsEmit::serialize(const SerializationOptions& options) const {
+Value ExpressionInternalJsEmit::serialize(bool explain) const {
     return Value(
         Document{{kExpressionName,
-                  Document{{"eval", _funcSource}, {"this", _thisRef->serialize(options)}}}});
+                  Document{{"eval", _funcSource}, {"this", _thisRef->serialize(explain)}}}});
 }
 
 Value ExpressionInternalJsEmit::evaluate(const Document& root, Variables* variables) const {
@@ -145,14 +145,11 @@ Value ExpressionInternalJsEmit::evaluate(const Document& root, Variables* variab
     ExpressionContext* expCtx = getExpressionContext();
 
     auto jsExec = expCtx->getJsExecWithScope();
-
-    // Inject the native "emit" function to be called from the user-defined map function.
-    //
-    // We reinject this function on every invocation of evaluate(), because there is a single
-    // JsExecution instance for the OperationContext, which may be shared by multiple aggregation
-    // pipelines and we need to ensure that the injected function still points to the valid
-    // contextual data ('_emitState').
-    jsExec->injectEmit(emitFromJS, &_emitState);
+    // Inject the native "emit" function to be called from the user-defined map function. This
+    // particular Expression/ExpressionContext may be reattached to a new OperationContext (and thus
+    // a new JS Scope) when used across getMore operations, so this method will handle that case for
+    // us by only injecting if we haven't already.
+    jsExec->injectEmitIfNecessary(emitFromJS, &_emitState);
 
     // Although inefficient to "create" a new function every time we evaluate, this will usually end
     // up being a simple cache lookup. This is needed because the JS Scope may have been recreated