A Rails 3 gotcha with html_safe

This was causing me to scratch my head a bit today. I'm glad I know what's going on now and why you need to use safe_concat. It still seems a little unintuitive though. For more into see the explanation here (under the "the tricky part") and the api docs on ActiveSupport::SafeBuffer

	#
	# This is pretty confusing until you know what's going on...
	#
	# See http://techspry.com/ruby_and_rails/html_safe-and-helpers-in-rails-3-mystery-solved/
	# for an explanation...
	#
	ruby-1.8.7-p334 :025 > foo_safe = "<p>foo</p>".html_safe
	=> "<p>foo</p>"
	ruby-1.8.7-p334 :026 > (foo_safe + "<p>bar</p>").html_safe # not what you thought! unintuitive!
	=> "<p>foo</p>&lt;p&gt;bar&lt;/p&gt;"
	ruby-1.8.7-p334 :027 > "#{foo_safe}<p>bar</p>".html_safe # I think it works because of the implicit to_s
	=> "<p>foo</p><p>bar</p>"
	ruby-1.8.7-p334 :028 > foo_safe.safe_concat("<p>bar</p>") # correct, but looks pretty clunky, right?
	=> "<p>foo</p><p>bar</p>"

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