(DOCS-15246): 4.2.20 changelog (#978)

* (DOCS-15246): 4.2.20 changelog

* add changelog include

Author: jeff-allen-mongo

source/includes/changelogs/releases/4.2.20.rst

@@ -0,0 +1,30 @@
+.. _4.2.20-changelog:
+
+4.2.20 Changelog
+----------------
+
+Sharding
+~~~~~~~~
+
+:issue:`SERVER-64903` Make cancel_coordinate_txn_commit_with_tickets_exhausted.js robust to ShardServerCatalogCacheLoader performing deletes
+
+Aggregation
+~~~~~~~~~~~
+
+:issue:`SERVER-41714` $facet operator duplicates documents in the pipeline when preceded by $addFields and $match operators (in this exact order)
+
+Internals
+~~~~~~~~~
+
+- :issue:`SERVER-53726` Platform Support: Remove RHEL6 zSeries
+- :issue:`SERVER-57000` Fix handling of correlated pipeline with facet
+- :issue:`SERVER-57676` Wait for a checkpoint before releasing the "hangOplogCapMaintainerThread" in oplog_rollover.js
+- :issue:`SERVER-59435` Fix a double free inside DocumentSource::optimizeAt()
+- :issue:`SERVER-60412` Host memory limit check does not honor cgroups v2 
+- :issue:`SERVER-62242` $indexOfArray does not work with duplicate values in array
+- :issue:`SERVER-63141` Difference in $lookup/$redact/$let behaviour with pipeline optimization
+- :issue:`SERVER-64642` Fix error where mongos returns CallbackCanceled and not InterruptedAtShutdown on shutdown
+- :issue:`SERVER-64983` Release Client lock before rolling back WT transaction in TransactionParticipant::_resetTransactionState
+- :issue:`SERVER-65421` Fix package test failures on RHEL 6/7
+- :issue:`SERVER-65422` Fix package test failures on Ubuntu 16.04
+

source/release-notes/4.2-changelog.txt

@@ -10,6 +10,8 @@
    :depth: 1
    :class: singlecol
 
+.. include:: /includes/changelogs/releases/4.2.20.rst
+
 .. include:: /includes/changelogs/releases/4.2.19.rst
 
 .. include:: /includes/changelogs/releases/4.2.18.rst

source/release-notes/4.2.txt

@@ -13,6 +13,30 @@ Release Notes for MongoDB 4.2
 Patch Releases
 --------------
 
+.. _4.2.20-release-notes:
+
+4.2.20 - Upcoming
+~~~~~~~~~~~~~~~~~
+
+Issues fixed in 4.2.20:
+
+- :issue:`SERVER-64983` Release Client lock before rolling back WT
+  transaction in TransactionParticipant::_resetTransactionState
+- :issue:`SERVER-60412` Host memory limit check does not honor cgroups
+  v2
+- :issue:`SERVER-64642` Fix error where mongos returns CallbackCanceled
+  and not InterruptedAtShutdown on shutdown
+- :issue:`SERVER-59435` Fix a double free inside
+  DocumentSource::optimizeAt()
+- :issue:`SERVER-41714` $facet operator duplicates documents in the
+  pipeline when preceded by $addFields and $match operators (in this
+  exact order)
+
+- `All JIRA issues closed in 4.2.20
+  <https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%274.2.20%27>`__
+
+- :ref:`4.2.20-changelog`
+
 .. _4.2.19-release-notes:
 
 4.2.19 - Mar 7, 2022