Dear zsh team,

I think I might have found a bug in zsh. Here is my bug report:

Steps to reproduce

	* add a simple RPROMPT to ~/.zshrc, e.g. RPROMPT='X'
	* optionally set PROMPT='$ ' to avoid side-effects of escape
	  sequences like color codes etc.

Actual outcome

	* the right prompt is not right aligned, it is in fact shifted to the
	  left by one character
	* this means that there is one character of space wasted
	* it is also optically disturbing, e.g. when using tmux and the
	  right prompt does not align with tmux's status bar

Expected outcome

	* the right prompt should be right aligned, using the full
	  available width of the terminal

Attached is a diff for zle_refresh.c that fixes the issue for me, although I now have to compile zsh myself. It would however be great to see this corrected in an official release of zsh. Thanks for your consideration!

Best,
Patrick