I'm pleased to announce version 1.12.0 of libbson and libmongoc,
the libraries constituting the MongoDB C Driver.

libbson

It is my pleasure to announce libbson 1.12.0. This release deprecates all
MD5-related public APIs; they will be removed in the next major release.

Bug fixes:

Properly handle zero-length BSON binary values
Fix crash parsing Base64-encoded data in JSON when using libbson without
libmongoc

libmongoc

It is my pleasure to announce the MongoDB C Driver 1.12.0.

Features:

New function mongoc_client_session_in_transaction to check if a multi-
document transaction is started.
New examples for change streams and transactions, improved guide for
migrating from mongoc_collection_count to mongoc_collection_count_documents

Bug fixes:

Fix occasional crash in sharded queries
Retry all retryable write concern errors
mongoc_client_session_commit_transaction sets the correct error label when
the primary is unavailable
mongoc_collection_find_with_opts had prohibited read preference "primary"
in a transaction
mongoc_collection_aggregate had not inherited its mongoc_collection_t's
read preference; only an explicitly provided read preference was used.
Allow unencoded delimiters in username/password if unambiguous