DOCSP-41360: v5.1.2 patch release

Author: rustagir

source/whats-new.txt

@@ -12,12 +12,36 @@ What's New
 
 Learn what's new in:
 
+* :ref:`Version 5.1.2 <kotlin-coroutine-version-5.1.2>`
 * :ref:`Version 5.1.1 <kotlin-coroutine-version-5.1.1>`
 * :ref:`Version 5.1 <kotlin-coroutine-version-5.1>`
 * :ref:`Version 5.0 <version-5.0>`
 * :ref:`Version 4.11 <version-4.11>`
 * :ref:`Version 4.10 <version-4.10>`
 
+.. _kotlin-coroutine-version-5.1.2:
+
+What's New in 5.1.2
+-------------------
+
+The 5.1.2 driver patch release includes the following changes:
+
+- Support for encoding Kotlin data classes with nullable
+  generic parameter types. For example, you can encode the ``Container`` class
+  in the following code:
+  
+  .. code-block:: kotlin
+
+     @Serializable
+     data class Box<T>(
+         val boxed: T
+     )
+     
+     @Serializable
+     data class Container(
+         val box: Box<String?>
+     )
+
 .. _kotlin-coroutine-version-5.1.1:
 
 What's New in 5.1.1