scroll

commit 79dd01d2f78326259f1dbdb3d4d124b94f7bcd8b
parent 5cfe13ab217d60cbfcdb6d7f5e60f5c290e5e3d1
Author: Jochen Sprickerhof <git@jochen.sprickerhof.de>
Date:   Sun,  5 Apr 2020 22:06:16 +0200

Fix some special cases in scrolling

Diffstat:
M
scroll.c
 | 
7
+++++--

1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/scroll.c b/scroll.c
@@ -283,21 +283,24 @@ scrollup(int n)
 		bottom = TAILQ_NEXT(bottom, entries);
 		write(STDOUT_FILENO, scrollend->buf, scrollend->size);
 	}
+	dprintf(STDOUT_FILENO, "\033[%d;%dH", ws.ws_row, ws.ws_col);
 }
 
 void
 scrolldown(char *buf, size_t size, int n)
 {
+	if (bottom == NULL || bottom == TAILQ_FIRST(&head))
+		return;
 	bottom = TAILQ_PREV(bottom, tailhead, entries);
 	/* print n lines */
 	for (; n > 0 && bottom != NULL && bottom != TAILQ_FIRST(&head); n--) {
 		bottom = TAILQ_PREV(bottom, tailhead, entries);
 		write(STDOUT_FILENO, bottom->buf, bottom->size);
 	}
-	if (bottom == TAILQ_FIRST(&head)) {
+	if (n > 0 && bottom == TAILQ_FIRST(&head)) {
 		write(STDOUT_FILENO, "\033[?25h", 6);	/* show cursor */
 		write(STDOUT_FILENO, buf, size);
-	} else
+	} else if (bottom != NULL)
 		bottom = TAILQ_NEXT(bottom, entries);
 }