1 files changed, 58 insertions, 2 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index ab17a2b438..c18403865f 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,6 +1,62 @@
+*   Ensure that mutations of the array returned from `ActiveRecord::Relation#to_a`
+    do not affect the original relation, by returning a duplicate array each time.
+
+    This brings the behavior in line with `CollectionProxy#to_a`, which was
+    already more careful.
+
+    *Matthew Draper*
+
+*   Fixed `where` for polymorphic associations when passed an array containing different types.
+
+    Fixes #17011.
+
+    Example:
+
+        PriceEstimate.where(estimate_of: [Treasure.find(1), Car.find(2)])
+        # => SELECT "price_estimates".* FROM "price_estimates"
+             WHERE (("price_estimates"."estimate_of_type" = 'Treasure' AND "price_estimates"."estimate_of_id" = 1)
+             OR ("price_estimates"."estimate_of_type" = 'Car' AND "price_estimates"."estimate_of_id" = 2))
+
+    *Philippe Huibonhoa*
+
+*   Fix a bug where using `t.foreign_key` twice with the same `to_table` within
+    the same table definition would only create one foreign key.
+
+    *George Millo*
+
+*   Fix a regression on has many association, where calling a child from parent in child's callback
+    results in same child records getting added repeatedly to target.
+
+    Fixes #13387.
+
+    *Bogdan Gusiev*, *Jon Hinson*
+
+*   Rework `ActiveRecord::Relation#last`.
+
+    1. Never perform additional SQL on loaded relation
+    2. Use SQL reverse order instead of loading relation if relation doesn't have limit
+    3. Deprecated relation loading when SQL order can not be automatically reversed
+
+        Topic.order("title").load.last(3)
+          # before: SELECT ...
+          # after: No SQL
+
+        Topic.order("title").last
+          # before: SELECT * FROM `topics`
+          # after:  SELECT * FROM `topics` ORDER BY `topics`.`title` DESC LIMIT 1
+
+        Topic.order("coalesce(author, title)").last
+          # before: SELECT * FROM `topics`
+          # after:  Deprecation Warning for irreversible order
+
+    *Bogdan Gusiev*
+
+
 *   Allow `joins` to be unscoped.
 
-    Closes #13775.
+    Fixes #13775.
+
+    *Takashi Kokubun*
 
 *   Add ActiveRecord `#second_to_last` and `#third_to_last` methods.
 
@@ -620,7 +676,7 @@
 
     *Ben Murphy*, *Matthew Draper*
 
-*   `bin/rake db:migrate` uses
+*   `bin/rails db:migrate` uses
     `ActiveRecord::Tasks::DatabaseTasks.migrations_paths` instead of
     `Migrator.migrations_paths`.