bulk: Handle upsert on MongoDB < 2.6 with non-objectid _id fields.

Server versions before 2.6 only return the 'upserted' field in an update
result when the upserted _id is an ObjectId. If the user provides any
other value for _id in the query spec, or update document (for a replace
operation) the upserted field is not returned. This causes invalid counts
for nUpserted in the Bulk API result set.

This fixes CDRIVER-372.

Author: Christian Hergert

src/mongoc/mongoc-write-command.c

@@ -933,6 +933,23 @@ _mongoc_write_result_merge_legacy (mongoc_write_result_t  *result, /* IN */
                }
             }
          }
+      } else if ((n == 1) &&
+                 bson_iter_init_find (&iter, reply, "updatedExisting") &&
+                 BSON_ITER_HOLDS_BOOL (&iter) &&
+                 !bson_iter_bool (&iter)) {
+         /*
+          * CDRIVER-372:
+          *
+          * Versions of MongoDB before 2.6 don't return the _id for an
+          * upsert if _id is not an ObjectId.
+          */
+         result->nUpserted += 1;
+         if (bson_iter_init_find (&iter, command->u.update.update, "_id") ||
+             bson_iter_init_find (&iter, command->u.update.selector, "_id")) {
+            value = bson_iter_value (&iter);
+            _mongoc_write_result_append_upsert (result, result->n_commands,
+                                                value);
+         }
       } else {
          result->nMatched += n;
       }

tests/test-bulk.c

@@ -292,6 +292,143 @@ test_index_offset (void)
 }
 
 
+static void
+test_bulk_edge_case_372 (void)
+{
+   mongoc_client_t *client;
+   mongoc_collection_t *collection;
+   mongoc_bulk_operation_t *bulk;
+   bson_error_t error;
+   bson_iter_t iter;
+   bson_iter_t citer;
+   bson_iter_t child;
+   const char *str;
+   bson_t *selector;
+   bson_t *update;
+   bson_t reply;
+   bool r;
+   int count;
+   int vmaj = 0;
+   int vmin = 0;
+   int vmic = 0;
+
+   client = mongoc_client_new (gTestUri);
+   assert (client);
+
+   collection = get_test_collection (client, "CDRIVER_372");
+   assert (collection);
+
+   bulk = mongoc_collection_create_bulk_operation (collection, true, NULL);
+   assert (bulk);
+
+   selector = BCON_NEW ("_id", BCON_INT32 (0));
+   update = BCON_NEW ("$set", "{", "a", BCON_INT32 (0), "}");
+   mongoc_bulk_operation_update_one (bulk, selector, update, true);
+   bson_destroy (selector);
+   bson_destroy (update);
+
+   selector = BCON_NEW ("a", BCON_INT32 (1));
+   update = BCON_NEW ("_id", BCON_INT32 (1));
+   mongoc_bulk_operation_replace_one (bulk, selector, update, true);
+   bson_destroy (selector);
+   bson_destroy (update);
+
+   r = mongoc_client_get_server_status (client, NULL, &reply, &error);
+   if (!r) fprintf (stderr, "%s\n", error.message);
+   assert (r);
+
+   if (bson_iter_init_find (&iter, &reply, "version") &&
+       BSON_ITER_HOLDS_UTF8 (&iter) &&
+       (str = bson_iter_utf8 (&iter, NULL))) {
+      sscanf (str, "%d.%d.%d", &vmaj, &vmin, &vmic);
+   }
+
+   bson_destroy (&reply);
+
+   if (vmaj >=2 || (vmaj == 2 && vmin >= 6)) {
+      /* This is just here to make the counts right in all cases. */
+      selector = BCON_NEW ("_id", BCON_INT32 (2));
+      update = BCON_NEW ("_id", BCON_INT32 (2));
+      mongoc_bulk_operation_replace_one (bulk, selector, update, true);
+      bson_destroy (selector);
+      bson_destroy (update);
+   } else {
+      /* This case is only possible in MongoDB versions before 2.6. */
+      selector = BCON_NEW ("_id", BCON_INT32 (3));
+      update = BCON_NEW ("_id", BCON_INT32 (2));
+      mongoc_bulk_operation_replace_one (bulk, selector, update, true);
+      bson_destroy (selector);
+      bson_destroy (update);
+   }
+
+   r = mongoc_bulk_operation_execute (bulk, &reply, &error);
+   if (!r) fprintf (stderr, "%s\n", error.message);
+   assert (r);
+
+#if 0
+   printf ("%s\n", bson_as_json (&reply, NULL));
+#endif
+
+   assert (bson_iter_init_find (&iter, &reply, "nMatched") &&
+           BSON_ITER_HOLDS_INT32 (&iter) &&
+           (0 == bson_iter_int32 (&iter)));
+   assert (bson_iter_init_find (&iter, &reply, "nUpserted") &&
+           BSON_ITER_HOLDS_INT32 (&iter) &&
+           (3 == bson_iter_int32 (&iter)));
+   assert (bson_iter_init_find (&iter, &reply, "nInserted") &&
+           BSON_ITER_HOLDS_INT32 (&iter) &&
+           (0 == bson_iter_int32 (&iter)));
+   assert (bson_iter_init_find (&iter, &reply, "nRemoved") &&
+           BSON_ITER_HOLDS_INT32 (&iter) &&
+           (0 == bson_iter_int32 (&iter)));
+
+   assert (bson_iter_init_find (&iter, &reply, "upserted") &&
+           BSON_ITER_HOLDS_ARRAY (&iter) &&
+           bson_iter_recurse (&iter, &citer));
+
+   assert (bson_iter_next (&citer));
+   assert (BSON_ITER_HOLDS_DOCUMENT (&citer));
+   assert (bson_iter_recurse (&citer, &child));
+   assert (bson_iter_find (&child, "_id"));
+   assert (BSON_ITER_HOLDS_INT32 (&child));
+   assert (0 == bson_iter_int32 (&child));
+   assert (bson_iter_recurse (&citer, &child));
+   assert (bson_iter_find (&child, "index"));
+   assert (BSON_ITER_HOLDS_INT32 (&child));
+   assert (0 == bson_iter_int32 (&child));
+
+   assert (bson_iter_next (&citer));
+   assert (BSON_ITER_HOLDS_DOCUMENT (&citer));
+   assert (bson_iter_recurse (&citer, &child));
+   assert (bson_iter_find (&child, "_id"));
+   assert (BSON_ITER_HOLDS_INT32 (&child));
+   assert (1 == bson_iter_int32 (&child));
+   assert (bson_iter_recurse (&citer, &child));
+   assert (bson_iter_find (&child, "index"));
+   assert (BSON_ITER_HOLDS_INT32 (&child));
+   assert (1 == bson_iter_int32 (&child));
+
+   assert (bson_iter_next (&citer));
+   assert (BSON_ITER_HOLDS_DOCUMENT (&citer));
+   assert (bson_iter_recurse (&citer, &child));
+   assert (bson_iter_find (&child, "_id"));
+   assert (BSON_ITER_HOLDS_INT32 (&child));
+   assert (2 == bson_iter_int32 (&child));
+   assert (bson_iter_recurse (&citer, &child));
+   assert (bson_iter_find (&child, "index"));
+   assert (BSON_ITER_HOLDS_INT32 (&child));
+   assert (2 == bson_iter_int32 (&child));
+
+   assert (!bson_iter_next (&citer));
+
+   bson_destroy (&reply);
+
+   mongoc_bulk_operation_destroy (bulk);
+   mongoc_collection_destroy (collection);
+   mongoc_client_destroy (client);
+}
+
+
 void
 test_bulk_install (TestSuite *suite)
 {
@@ -300,6 +437,7 @@ test_bulk_install (TestSuite *suite)
    TestSuite_Add (suite, "/BulkOperation/basic", test_bulk);
    TestSuite_Add (suite, "/BulkOperation/update_upserted", test_update_upserted);
    TestSuite_Add (suite, "/BulkOperation/index_offset", test_index_offset);
+   TestSuite_Add (suite, "/BulkOperation/CDRIVER-372", test_bulk_edge_case_372);
 
    atexit (cleanup_globals);
 }