Re: [9fans] invisible prompt in win

["Russ Cox" <rsc@swtch.com>]

This is not a bug.

At any point in time, there is a character position
associated with the upper left corner of the text window.
Text before that position is not shown; text at or after
that position is shown, until it runs off the bottom of
the window.  Let's call that upper left character position p0.

Most of the time, acme/sam/rio work to arrange that p0
follows a newline character, so that the window begins
at the beginning of a line.  Sometimes this is not possible.
One case is when a line is very long--longer than the
entire window--and you want to see the end of it.
Another case is when you tell acme/sam/rio to scroll past
the end of the text.  Then p0 is the end of the text,
right where your cursor is.  When you type new text,
it correctly shows at p0.  The prompt is still there, just
off the window to the top.

You are expecting line-oriented behavior in a "stream of bytes" world.

Russ