Fix collection_from_options to allow Enumerators

An optimization was introduced in
https://github.com/rails/rails/commit/27f4ffd11a91b534fde9b484cb7c4e515ec0fe77
which tried to `#to_ary` the collection to prevent unnecessary queries
for ActiveRecord scopes/relations. If the given collection did not
respond to `#to_ary`, and empty collection was returned. That meant you
couldn't use collections built from `Enumerator` nor `Enumerable`.

With this change, `#collection_from_options` will attempt the
optimization, but fall back to passing along the given collection,
as-is.

1 files changed, 11 insertions, 0 deletions

diff --git a/actionview/CHANGELOG.md b/actionview/CHANGELOG.md
index ab4b46c56e..987d062540 100644
--- a/actionview/CHANGELOG.md
+++ b/actionview/CHANGELOG.md
@@ -1,3 +1,14 @@
+*   Changed partial rendering with a collection to allow collections which
+    don't implement `to_ary`.
+
+    Extracting the collection option has an optimization to avoid unnecessary
+    queries of ActiveRecord Relations by calling `to_ary` on the given
+    collection. Instances of `Enumerator` or `Enumerable` are valid
+    collections, but they do not implement `#to_ary`. They will now be
+    extracted and rendered as expected.
+
+    *Steven Harman*
+
 *   New syntax for tag helpers. Avoid positional parameters and support HTML5 by default.
     Example usage of tag helpers before: