Do not generate dummy string when the tag used is not the <%=

railties/lib/rails/application/dummy_erb_compiler.rb

@@ -11,6 +11,9 @@ end
 
 class DummyCompiler < ERB::Compiler # :nodoc:
   def compile_content(stag, out)
-    out.push "_erbout << 'dummy_compiler'"
+    case stag
+    when '<%='
+      out.push "_erbout << 'dummy_compiler'"
+    end
   end
 end

railties/test/application/rake/dbs_test.rb

@@ -53,6 +53,7 @@ module ApplicationTests
 
       test "db:create and db:drop respect environment setting" do
         app_file "config/database.yml", <<-YAML
+          <% 1  %>
           development:
             database: <%= Rails.application.config.database %>
             adapter: sqlite3