Prevent negative values for offset and pos in push_link()

Bug-Debian: https://github.com/tats/w3m/issues/64

1 files changed, 6 insertions, 2 deletions

diff --git a/file.c b/file.c
index 134df82..35034ce 100644
--- a/file.c
+++ b/file.c
@@ -2311,8 +2311,12 @@ 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;
 }