Re: Mac OS X Prompt Bug

[Bart Schaefer <schaefer@brasslantern.com>]

On Nov 24,  4:14pm, Sorin Ionescu wrote:
}
} There is no /etc/zshprofile, /etc/zshrc or any other combination.
} /etc/profile is not sourced.
}
} I have found nothing in the output of zsh -l -x. Like I said, it's
} not a configuration issue. It's something in ZSH or Terminal.app or
} both. Nothing hooks on those functions. It's possible that ZSH outputs
} some sequences Terminal.app does not like and generates those lines.

Things that zsh might be doing when the window first opens include
closing and re-opening the standard I/O streams, reading the name
of the terminal device with ttyname(), setting the close-on-exec
flag on some descriptors, and reading the size of the terminal from
ioctl().  It might also repeat that last a few times if it receives
WINCH signals.

You could try putting a TRAPWINCH function in your ~/.zshenv file
to see if that's called when the blank lines are printed.  Otherwise
you're going to have to resort to some sort of debugger or system
call trace.