SERVER-8046 Cleanup Element::writeArrayTo and add a test for the new implementation

1 files changed, 6 insertions, 4 deletions

diff --git a/src/mongo/bson/mutable/element.cpp b/src/mongo/bson/mutable/element.cpp
index 79de5b073ec..746c4c43dbe 100644
--- a/src/mongo/bson/mutable/element.cpp
+++ b/src/mongo/bson/mutable/element.cpp
@@ -158,10 +158,12 @@ namespace mutablebson {
             BSONObj obj = builder.obj();
             return obj.firstElement().toString();
         } else if (isType(mongo::Array)) {
-            BSONArrayBuilder builder;
-            writeArrayTo(&builder);
-            BSONArray arr = builder.arr();
-            return arr.firstElement().toString();
+            BSONObjBuilder builder;
+            BSONArrayBuilder arrayBuilder(builder.subarrayStart(getFieldName()));
+            writeArrayTo(&arrayBuilder);
+            arrayBuilder.done();
+            BSONObj obj = builder.obj();
+            return obj.firstElement().toString();
         } else {
             return "corrupted element";
         }