Merge pull request #23472 from jhubert/patch-2

Remove the assumption of schema in DATABASE_URL

activerecord/lib/active_record/connection_adapters/connection_specification.rb

@@ -33,7 +33,7 @@ class ConnectionUrlResolver # :nodoc:
         def initialize(url)
           raise "Database URL cannot be empty" if url.blank?
           @uri     = uri_parser.parse(url)
-          @adapter = @uri.scheme.tr('-', '_')
+          @adapter = @uri.scheme && @uri.scheme.tr('-', '_')
           @adapter = "postgresql" if @adapter == "postgres"
 
           if @uri.opaque

activerecord/test/cases/connection_specification/resolver_test.rb

@@ -57,6 +57,12 @@ def test_url_host_no_db
             "encoding" => "utf8" }, spec)
         end
 
+        def test_url_missing_scheme
+          spec = resolve 'foo'
+          assert_equal({
+            "database" => "foo" }, spec)
+        end
+
         def test_url_host_db
           spec = resolve 'abstract://foo/bar?encoding=utf8'
           assert_equal({