Subject: Prevent negative array index for marks in shiftAnchorPosition()
From: Tatsuya Kinoshita <tats@debian.org>
Bug-Debian: https://github.com/tats/w3m/issues/62
Origin: https://anonscm.debian.org/cgit/collab-maint/w3m.git/commit/?id=d57c13282afc6b7dca029f992331b7afa0413356

---
 anchor.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/anchor.c b/anchor.c
index ecb211d..bed8db2 100644
--- a/anchor.c
+++ b/anchor.c
@@ -551,7 +551,8 @@ shiftAnchorPosition(AnchorList *al, HmarkerList *hl, int line, int pos,
 	    break;
 	if (a->start.pos > pos) {
 	    a->start.pos += shift;
-	    if (hl && hl->marks && hl->marks[a->hseq].line == line)
+	    if (hl && hl->marks &&
+		a->hseq >= 0 && hl->marks[a->hseq].line == line)
 		hl->marks[a->hseq].pos = a->start.pos;
 	}
 	if (a->end.pos >= pos)
-- 
2.10.2