Prevent negative values for offset and pos in push_link()

Bug-Debian: https://github.com/tats/w3m/issues/64
Bug-Debian: https://github.com/tats/w3m/issues/66
Origin: https://anonscm.debian.org/cgit/collab-maint/w3m.git/commit/?id=ecf57714191b77142da74035b748262cdc80dfb7

1 files changed, 6 insertions, 2 deletions

diff --git a/file.c b/file.c
index 330ae3a..483180a 100644
--- a/file.c
+++ b/file.c
@@ -2307,8 +2307,12 @@ push_link(int cmd, int offset, int pos)
     struct link_stack *p;
     p = New(struct link_stack);
     p->cmd = cmd;
-    p->offset = offset;
-    p->pos = pos;
+    p->offset = (short)offset;
+    if (p->offset < 0)
+	p->offset = 0;
+    p->pos = (short)pos;
+    if (p->pos < 0)
+	p->pos = 0;
     p->next = link_stack;
     link_stack = p;
 }