Background & Motivation

C driver API which accepts a bson_t* reply expects the reply to be uninitialized. This is inconsistently documented.

mongoc_collection_command_simple notes:

reply: A location to initialize a bson_t. This should be on the stack.

mongoc_database_command_simple notes:

reply: A location to store the commands first result document.

mongoc_client_session_commit_transaction notes:

reply: An optional uninitialized bson_t to receive the server reply, or NULL.

Scope
Audit the documentation for all API methods that take a bson_t* reply and consistently document that the reply must be uninitialized and cannot be the pointer returned by bson_new.