fix namespaced schema load ignoring protected env

This makes the task requirements for db:schema:load:namespace the same
as db:schema:load (adding check_protected_environments)

activerecord/lib/active_record/railties/databases.rake

@@ -484,7 +484,7 @@ db_namespace = namespace :db do
     namespace :load do
       ActiveRecord::Tasks::DatabaseTasks.for_each(databases) do |name|
         desc "Loads a database schema file (either db/schema.rb or db/structure.sql, depending on `config.active_record.schema_format`) into the #{name} database"
-        task name => :load_config do
+        task name => [:load_config, :check_protected_environments] do
           original_db_config = ActiveRecord::Base.connection_db_config
           db_config = ActiveRecord::Base.configurations.configs_for(env_name: ActiveRecord::Tasks::DatabaseTasks.env, name: name)
           ActiveRecord::Tasks::DatabaseTasks.load_schema(db_config)

railties/test/application/rake/dbs_test.rb

@@ -723,6 +723,24 @@ module ApplicationTests
           assert_match(/Dropped database/, repeat_output)
         end
       end
+
+      test "destructive tasks are protected" do
+        add_to_config "config.active_record.protected_environments = ['development', 'test']"
+
+        require "#{app_path}/config/environment"
+
+        Dir.chdir(app_path) do
+          rails "generate", "model", "book", "title:string"
+          rails "db:migrate"
+
+          destructive_tasks = ["db:drop:all", "db:drop", "db:purge:all", "db:truncate_all", "db:purge", "db:schema:load", "db:test:purge"]
+
+          destructive_tasks.each do |task|
+            error = assert_raises("#{task} did not raise ActiveRecord::ProtectedEnvironmentError") { rails task }
+            assert_match(/ActiveRecord::ProtectedEnvironmentError/, error.message)
+          end
+        end
+      end
     end
   end
 end

railties/test/application/rake/multi_dbs_test.rb

@@ -1135,6 +1135,24 @@ module ApplicationTests
           assert_equal "true", animals_db_exists.call
         end
       end
+
+      test "destructive tasks are protected" do
+        add_to_config "config.active_record.protected_environments = ['development', 'test']"
+
+        require "#{app_path}/config/environment"
+
+        Dir.chdir(app_path) do
+          generate_models_for_animals
+          rails "db:migrate"
+
+          destructive_tasks = ["db:drop:animals", "db:schema:load:animals", "db:test:purge:animals"]
+
+          destructive_tasks.each do |task|
+            error = assert_raises("#{task} did not raise ActiveRecord::ProtectedEnvironmentError") { rails task }
+            assert_match(/ActiveRecord::ProtectedEnvironmentError/, error.message)
+          end
+        end
+      end
     end
   end
 end