MINOR: ncbuf: complete doc for ncb_advance()
ncb_advance() operation may reject the operation if a too small gap is
formed in buffer front. This must be documented to avoid an issue with
it.
This should be backported up to 2.6.
diff --git a/src/ncbuf.c b/src/ncbuf.c
index 1202939..ed1878b 100644
--- a/src/ncbuf.c
+++ b/src/ncbuf.c
@@ -625,7 +625,9 @@
* will be lost while some space will be formed at the end to be able to insert
* new data.
*
- * Returns NCB_RET_OK on success.
+ * Returns NCB_RET_OK on success. It may return NCB_RET_GAP_SIZE if operation
+ * is rejected due to the formation of a too small gap in front. If advance is
+ * done only inside a data block it is guaranteed to succeed.
*/
enum ncb_ret ncb_advance(struct ncbuf *buf, ncb_sz_t adv)
{