buffers: comment added in buf_shrink.

* buf.c (buf_shrink): It's not immediately obvious why len is
incremented by one if it is zero.

1 files changed, 1 insertions, 1 deletions

diff --git a/buf.c b/buf.c
index 910d7801..ce196976 100644
--- a/buf.c
+++ b/buf.c
@@ -175,7 +175,7 @@ static void buf_shrink(struct buf *b)
   val len = b->len;
 
   if (len == zero)
-    len = succ(len);
+    len = succ(len); /* avoid reallocing to zero length; i.e. freeing */
 
   if (len != b->size) {
     b->data = chk_realloc(b->data, c_num(len));