Control reading off the edge of our buffer in term_flushln().

This happens in specific conditions (trailing whitespace in certain
terminal modes), but in practise, it happens quite often (as reported by
valgrind).
In short, "Nothing about term_flushln() is simple.  Srsly!" (schwarze@)
Discussed on tech@, ok schwarze@.

1 files changed, 1 insertions, 1 deletions

diff --git a/term.c b/term.c
index fb00fa62..f1e959a2 100644
--- a/term.c
+++ b/term.c
@@ -220,7 +220,7 @@ term_flushln(struct termp *p)
 				break;
 			if (' ' == p->buf[i]) {
 				j = i;
-				while (' ' == p->buf[i])
+				while (i < p->col && ' ' == p->buf[i])
 					i++;
 				dv = (i - j) * (*p->width)(p, ' ');
 				vbl += dv;