4 files changed, 27 insertions, 6 deletions

diff --git a/src/mongo/s/write_ops/batch_downconvert.cpp b/src/mongo/s/write_ops/batch_downconvert.cpp
index 068ab1599aa..cdfa9264cac 100644
--- a/src/mongo/s/write_ops/batch_downconvert.cpp
+++ b/src/mongo/s/write_ops/batch_downconvert.cpp
@@ -180,6 +180,9 @@ namespace mongo {
         // N starts at zero, and we add to it for each item
         response->setN( 0 );
 
+        // GLE path always sets nModified to -1 (sentinel) to indicate we should omit it later.
+        response->setNModified(-1);
+
         for ( size_t i = 0; i < request.sizeWriteOps(); ++i ) {
 
             // Break on first error if we're ordered
diff --git a/src/mongo/s/write_ops/batch_write_op.cpp b/src/mongo/s/write_ops/batch_write_op.cpp
index 0a3dfd8a055..8f0688eaef2 100644
--- a/src/mongo/s/write_ops/batch_write_op.cpp
+++ b/src/mongo/s/write_ops/batch_write_op.cpp
@@ -449,7 +449,13 @@ namespace mongo {
                 numUpserted = response.sizeUpsertDetails();
             }
             stats->numMatched += ( response.getN() - numUpserted );
-            stats->numModified += response.getNModified();
+            long long numModified = response.getNModified();
+
+            if (numModified >= 0)
+                stats->numModified += numModified;
+            else
+                stats->numModified = -1; // sentinel used to indicate we omit the field downstream
+
             stats->numUpserted += numUpserted;
         }
         else {
@@ -740,8 +746,10 @@ namespace mongo {
         int nValue = _stats->numInserted + _stats->numUpserted + _stats->numMatched
                      + _stats->numDeleted;
         batchResp->setN( nValue );
-        if ( _clientRequest->getBatchType() == BatchedCommandRequest::BatchType_Update )
-            batchResp->setNModified( _stats->numModified );
+        if ( _clientRequest->getBatchType() == BatchedCommandRequest::BatchType_Update &&
+             _stats->numModified >= 0) {
+                batchResp->setNModified( _stats->numModified );
+        }
 
         dassert( batchResp->isValid( NULL ) );
     }
diff --git a/src/mongo/s/write_ops/batch_write_op.h b/src/mongo/s/write_ops/batch_write_op.h
index cf058a5ec23..0237bb6185d 100644
--- a/src/mongo/s/write_ops/batch_write_op.h
+++ b/src/mongo/s/write_ops/batch_write_op.h
@@ -192,6 +192,16 @@ namespace mongo {
         int numModified;
         int numDeleted;
 
+        std::string toString() const {
+            StringBuilder str;
+            str << "numInserted: " << numInserted
+                << " numUpserted: " << numUpserted
+                << " numMatched: " << numMatched
+                << " numModified: " << numModified
+                << " numDeleted: " << numDeleted;
+            return str.str();
+        }
+
     };
 
     /**
diff --git a/src/mongo/s/write_ops/batched_command_response.cpp b/src/mongo/s/write_ops/batched_command_response.cpp
index 7c15c04196d..f412f6d59d9 100644
--- a/src/mongo/s/write_ops/batched_command_response.cpp
+++ b/src/mongo/s/write_ops/batched_command_response.cpp
@@ -39,7 +39,7 @@ namespace mongo {
     const BSONField<int> BatchedCommandResponse::errCode("code", ErrorCodes::UnknownError);
     const BSONField<string> BatchedCommandResponse::errMessage("errmsg");
     const BSONField<long long> BatchedCommandResponse::n("n", 0);
-    const BSONField<long long> BatchedCommandResponse::nModified("nModified", -1);
+    const BSONField<long long> BatchedCommandResponse::nModified("nModified", 0);
     const BSONField<std::vector<BatchedUpsertDetail*> >
         BatchedCommandResponse::upsertDetails("upserted");
     const BSONField<OpTime> BatchedCommandResponse::lastOp("lastOp");
@@ -81,7 +81,7 @@ namespace mongo {
 
         if (_isErrMessageSet) builder.append(errMessage(), _errMessage);
 
-        if (_isNModifiedSet && _nModified > -1) builder.appendNumber(nModified(), _nModified);
+        if (_isNModifiedSet) builder.appendNumber(nModified(), _nModified);
         if (_isNSet) builder.appendNumber(n(), _n);
 
         if (_upsertDetails.get()) {
@@ -203,7 +203,7 @@ namespace mongo {
         _errMessage.clear();
         _isErrMessageSet = false;
 
-        _nModified = -1;
+        _nModified = 0;
         _isNModifiedSet = false;
 
         _n = 0;