Deprecate `false` as the way to halt AR callbacks

Before this commit, returning `false` in an ActiveRecord `before_` callback
such as `before_create` would halt the callback chain.

After this commit, the behavior is deprecated: will still work until
the next release of Rails but will also display a deprecation warning.

The preferred way to halt a callback chain is to explicitly `throw(:abort)`.

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/test/models/bulb.rb b/activerecord/test/models/bulb.rb
index 831a0d5387..a6e83fe353 100644
--- a/activerecord/test/models/bulb.rb
+++ b/activerecord/test/models/bulb.rb
@@ -46,6 +46,6 @@ end
 
 class FailedBulb < Bulb
   before_destroy do
-    false
+    throw(:abort)
   end
 end