Fix two-level database configurations with URLs

An entry in `ActiveRecord::Base.configurations` can either be a
connection spec ("two-level") or a hash of specs ("three-level").

We were detecting two-level configurations by looking for the `database`
key, but the database can also be specified as part of the `url` key,
which meant we incorrectly treated those configurations as three-level.

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/database_configurations.rb b/activerecord/lib/active_record/database_configurations.rb
index 1c7a5d1347..09aef62753 100644
--- a/activerecord/lib/active_record/database_configurations.rb
+++ b/activerecord/lib/active_record/database_configurations.rb
@@ -43,7 +43,7 @@ module ActiveRecord
     # Given an env, spec and config creates DatabaseConfig structs with
     # each attribute set.
     def self.walk_configs(env_name, spec_name, config) # :nodoc:
-      if config["database"] || env_name == "default"
+      if config["database"] || config["url"] || env_name == "default"
         DatabaseConfig.new(env_name, spec_name, config)
       else
         config.each_pair.map do |sub_spec_name, sub_config|