DEV: Re-exec rake after creating database (#31120)

By design, db:create initializes the Rails app with SKIP_DB=true. That
means that SiteSettings get set up with the LocalProcessProvider instead
of the DBProvider. In other words: any calls to site settings will
return the default, rather then the actual value in the database.

Running db:migrate in the same rake invocation means that rails will not
be re-initialized, and so skip_db will remain true. Site settings
accessed during migrations and fixtures will therefore return incorrect
values.

One example of this is that running bin/rake db:create db:migrate
repeatedly in a development environment will cause the FAQ topic to be
seeded repeatedly, because the seed logic does not have access to the
site setting which stores the already-seeded topic id.

This commit will automatically re-exec the Rake command if any tasks are
specified after `db:create`

lib/tasks/db.rake

@@ -54,7 +54,14 @@ end
 begin
   reqs = Rake::Task["db:create"].prerequisites.map(&:to_sym)
   Rake::Task["db:create"].clear_prerequisites
-  Rake::Task["db:create"].enhance(["db:force_skip_persist"] + reqs)
+  Rake::Task["db:create"].enhance(["db:force_skip_persist"] + reqs) do
+    # after creating the db, we need to fully reboot the Rails app to make sure
+    # things like SiteSetting work correctly for future rake tasks.
+    db_create_index = ARGV.find_index("db:create")
+    if db_create_index < ARGV.length - 1
+      exec "#{Rails.root}/bin/rake", *ARGV[db_create_index + 1..-1]
+    end
+  end
 end
 
 task "db:drop" => [:load_config] do |_, args|