From: noname <noname@inventati.org>
Date: Sun, 20 Apr 2014 13:26:13 +0000 (+0400)
Subject: Use tsetdirt in tscrollup and tscrolldown.
X-Git-Url: https://git.xinqibao.xyz/st.git/commitdiff_plain/3afdb4ff04b45a5e4209a56d5073341c9d506b38?ds=inline;hp=3afdb4ff04b45a5e4209a56d5073341c9d506b38

Use tsetdirt in tscrollup and tscrolldown.

tscrollup and tscrolldown do not use tsetdirt, but their code is
equivalent to

        tsetdirt(orig, term.bot-n);
        tsetdirt(orig+n, term.bot);

tclearregion also marks cleared lines as dirty.
In tscrolldown it sets lines from term.bot-n+1 to term.bot dirty, and in
tscrollup it sets lines from orig to orig+n-1 dirty.

In both functions all lines from orig to term.bot are effectively set
dirty, but in tscrolldown lines from orig+n to term.bot are set dirty
twice, and in tscrollup lines from orig to term.bot-n are set dirty
twice.

These patches make it clear which lines are set dirty and sets them
dirty once in each funciton.
---