2nd patch for spdylay issue69, to give lower priority streams more chance to deliver output.

spdylay-issues69.patch

diff --git a/lib/spdylay_outbound_item.h b/lib/spdylay_outbound_item.h
index 12db6a6..21ebef9 100644
--- a/lib/spdylay_outbound_item.h
+++ b/lib/spdylay_outbound_item.h
@@ -50,6 +50,7 @@ typedef struct {
   spdylay_frame_category frame_cat;
   void *frame;
   void *aux_data;
+  int inipri;
   int pri;
   int64_t seq;
 } spdylay_outbound_item;
diff --git a/lib/spdylay_session.c b/lib/spdylay_session.c
index f4d6961..2fed907 100644
--- a/lib/spdylay_session.c
+++ b/lib/spdylay_session.c
@@ -444,6 +444,7 @@ int spdylay_session_add_frame(spdylay_session *session,
     free(item);
     return r;
   }
+  item->inipri = item->pri;
   return 0;
 }
 
@@ -1246,6 +1247,16 @@ spdylay_outbound_item* spdylay_session_pop_next_ob_item
   }
 }
 
+static void spdylay_outbound_item_adjust_pri(spdylay_session *session,
+                                             spdylay_outbound_item *item)
+{
+  if(item->pri > spdylay_session_get_pri_lowest(session)) {
+    item->pri = item->inipri;
+  } else {
+    ++item->pri;
+  }
+}
+
 /*
  * Called after a frame is sent.
  *
@@ -1400,6 +1411,7 @@ static int spdylay_session_after_frame_sent(spdylay_session *session)
     } else {
       spdylay_outbound_item* next_item;
       next_item = spdylay_session_get_next_ob_item(session);
+      spdylay_outbound_item_adjust_pri(session, session->aob.item);
       /* If priority of this stream is higher or equal to other stream
          waiting at the top of the queue, we continue to send this
          data. */