SERVER-39521 Don't skip _id in ObjWrapper::toBSON

We incorrectly checked for _id with alreadyHasOwnField, instead of
hasOwnField, which caused us to miss _id fields set from c++.

3 files changed, 49 insertions, 2 deletions

diff --git a/src/mongo/scripting/mozjs/db.cpp b/src/mongo/scripting/mozjs/db.cpp
index 228cd3d4acc..4748e9a308b 100644
--- a/src/mongo/scripting/mozjs/db.cpp
+++ b/src/mongo/scripting/mozjs/db.cpp
@@ -75,7 +75,7 @@ void DBInfo::resolve(JSContext* cx, JS::HandleObject obj, JS::HandleId id, bool*
     }
 
     // Check if this exists on the parent, ie. DBCollection::resolve case
-    if (parentWrapper.hasOwnField(id)) {
+    if (parentWrapper.alreadyHasOwnField(id)) {
         parentWrapper.getValue(id, &coll);
 
         o.defineProperty(id, coll, 0);
diff --git a/src/mongo/scripting/mozjs/objectwrapper.cpp b/src/mongo/scripting/mozjs/objectwrapper.cpp
index 306c1f4ef64..3c57e262029 100644
--- a/src/mongo/scripting/mozjs/objectwrapper.cpp
+++ b/src/mongo/scripting/mozjs/objectwrapper.cpp
@@ -203,6 +203,41 @@ bool ObjectWrapper::Key::hasOwn(JSContext* cx, JS::HandleObject o) {
 
     switch (_type) {
         case Type::Field:
+            if (JS_HasOwnProperty(cx, o, _field, &has))
+                return has;
+            break;
+        case Type::Index: {
+            JS::RootedId id(cx);
+
+            // This is a little different because there is no JS_HasOwnElement
+            if (JS_IndexToId(cx, _idx, &id) && JS_HasOwnPropertyById(cx, o, id, &has))
+                return has;
+            break;
+        }
+        case Type::Id: {
+            JS::RootedId id(cx, _id);
+
+            if (JS_HasOwnPropertyById(cx, o, id, &has))
+                return has;
+            break;
+        }
+        case Type::InternedString: {
+            InternedStringId id(cx, _internedString);
+
+            if (JS_HasOwnPropertyById(cx, o, id, &has))
+                return has;
+            break;
+        }
+    }
+
+    throwCurrentJSException(cx, ErrorCodes::InternalError, "Failed to hasOwn value on a JSObject");
+}
+
+bool ObjectWrapper::Key::alreadyHasOwn(JSContext* cx, JS::HandleObject o) {
+    bool has;
+
+    switch (_type) {
+        case Type::Field:
             if (JS_AlreadyHasOwnProperty(cx, o, _field, &has))
                 return has;
             break;
@@ -226,7 +261,8 @@ bool ObjectWrapper::Key::hasOwn(JSContext* cx, JS::HandleObject o) {
         }
     }
 
-    throwCurrentJSException(cx, ErrorCodes::InternalError, "Failed to hasOwn value on a JSObject");
+    throwCurrentJSException(
+        cx, ErrorCodes::InternalError, "Failed to alreadyHasOwn value on a JSObject");
 }
 
 void ObjectWrapper::Key::del(JSContext* cx, JS::HandleObject o) {
@@ -456,6 +492,10 @@ bool ObjectWrapper::hasOwnField(Key key) {
     return key.hasOwn(_context, _object);
 }
 
+bool ObjectWrapper::alreadyHasOwnField(Key key) {
+    return key.alreadyHasOwn(_context, _object);
+}
+
 void ObjectWrapper::callMethod(const char* field,
                                const JS::HandleValueArray& args,
                                JS::MutableHandleValue out) {
diff --git a/src/mongo/scripting/mozjs/objectwrapper.h b/src/mongo/scripting/mozjs/objectwrapper.h
index 7516807b130..ea006f82523 100644
--- a/src/mongo/scripting/mozjs/objectwrapper.h
+++ b/src/mongo/scripting/mozjs/objectwrapper.h
@@ -85,6 +85,7 @@ public:
         void set(JSContext* cx, JS::HandleObject o, JS::HandleValue value);
         bool has(JSContext* cx, JS::HandleObject o);
         bool hasOwn(JSContext* cx, JS::HandleObject o);
+        bool alreadyHasOwn(JSContext* cx, JS::HandleObject o);
         void define(
             JSContext* cx, JS::HandleObject o, unsigned attrs, JSNative getter, JSNative setter);
         void define(JSContext* cx, JS::HandleObject o, JS::HandleValue value, unsigned attrs);
@@ -138,9 +139,15 @@ public:
 
     void rename(Key key, const char* to);
 
+    // has field walks the prototype heirarchy
     bool hasField(Key key);
+
+    // has own field checks for the field directly on the object
     bool hasOwnField(Key key);
 
+    // already how own field checks for the field directly on the object, ignoring C++ hooks
+    bool alreadyHasOwnField(Key key);
+
     void callMethod(const char* name, const JS::HandleValueArray& args, JS::MutableHandleValue out);
     void callMethod(const char* name, JS::MutableHandleValue out);
     void callMethod(JS::HandleValue fun,