From 774dae135b5e73fbd6c8e7cb1ce70f7a6977d48d Mon Sep 17 00:00:00 2001
From: Erik Boasson <eb@ilities.com>
Date: Thu, 18 Jul 2019 19:16:43 +0200
Subject: [PATCH] Assertion rsample_is_singleton fails

Caused by the changes in a652ecb78e145fa936b8fef2f58f27ab0411245a; the
sample that matters is the first in what may now be a chain of samples,
which requires some overlooked adjustments.

Signed-off-by: Erik Boasson <eb@ilities.com>
---
 src/core/ddsi/include/dds/ddsi/q_radmin.h | 2 +-
 src/core/ddsi/src/q_radmin.c              | 7 ++++---
 src/core/ddsi/src/q_receive.c             | 4 +++-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/core/ddsi/include/dds/ddsi/q_radmin.h b/src/core/ddsi/include/dds/ddsi/q_radmin.h
index f05c512..69e2010 100644
--- a/src/core/ddsi/include/dds/ddsi/q_radmin.h
+++ b/src/core/ddsi/include/dds/ddsi/q_radmin.h
@@ -217,7 +217,7 @@ int nn_defrag_nackmap (struct nn_defrag *defrag, seqno_t seq, uint32_t maxfragnu
 
 struct nn_reorder *nn_reorder_new (enum nn_reorder_mode mode, uint32_t max_samples);
 void nn_reorder_free (struct nn_reorder *r);
-struct nn_rsample *nn_reorder_rsample_dup (struct nn_rmsg *rmsg, struct nn_rsample *rsampleiv);
+struct nn_rsample *nn_reorder_rsample_dup_first (struct nn_rmsg *rmsg, struct nn_rsample *rsampleiv);
 struct nn_rdata *nn_rsample_fragchain (struct nn_rsample *rsample);
 nn_reorder_result_t nn_reorder_rsample (struct nn_rsample_chain *sc, struct nn_reorder *reorder, struct nn_rsample *rsampleiv, int *refcount_adjust, int delivery_queue_full_p);
 nn_reorder_result_t nn_reorder_gap (struct nn_rsample_chain *sc, struct nn_reorder *reorder, struct nn_rdata *rdata, seqno_t min, seqno_t maxp1, int *refcount_adjust);
diff --git a/src/core/ddsi/src/q_radmin.c b/src/core/ddsi/src/q_radmin.c
index 039e591..738e714 100644
--- a/src/core/ddsi/src/q_radmin.c
+++ b/src/core/ddsi/src/q_radmin.c
@@ -1726,7 +1726,7 @@ static int reorder_try_append_and_discard (struct nn_reorder *reorder, struct nn
   }
 }
 
-struct nn_rsample *nn_reorder_rsample_dup (struct nn_rmsg *rmsg, struct nn_rsample *rsampleiv)
+struct nn_rsample *nn_reorder_rsample_dup_first (struct nn_rmsg *rmsg, struct nn_rsample *rsampleiv)
 {
   /* Duplicates the rsampleiv without updating any reference counts:
      that is left to the caller, as they do not need to be updated if
@@ -1738,7 +1738,6 @@ struct nn_rsample *nn_reorder_rsample_dup (struct nn_rmsg *rmsg, struct nn_rsamp
      rsampleiv. */
   struct nn_rsample *rsampleiv_new;
   struct nn_rsample_chain_elem *sce;
-  assert (rsample_is_singleton (&rsampleiv->u.reorder));
 #ifndef NDEBUG
   {
     struct nn_rdata *d = rsampleiv->u.reorder.sc.first->fragchain;
@@ -1754,7 +1753,9 @@ struct nn_rsample *nn_reorder_rsample_dup (struct nn_rmsg *rmsg, struct nn_rsamp
   sce->fragchain = rsampleiv->u.reorder.sc.first->fragchain;
   sce->next = NULL;
   sce->sampleinfo = rsampleiv->u.reorder.sc.first->sampleinfo;
-  *rsampleiv_new = *rsampleiv;
+  rsampleiv_new->u.reorder.min = rsampleiv->u.reorder.min;
+  rsampleiv_new->u.reorder.maxp1 = rsampleiv_new->u.reorder.min + 1;
+  rsampleiv_new->u.reorder.n_samples = 1;
   rsampleiv_new->u.reorder.sc.first = rsampleiv_new->u.reorder.sc.last = sce;
   return rsampleiv_new;
 }
diff --git a/src/core/ddsi/src/q_receive.c b/src/core/ddsi/src/q_receive.c
index 4d97333..a7d4036 100644
--- a/src/core/ddsi/src/q_receive.c
+++ b/src/core/ddsi/src/q_receive.c
@@ -2201,8 +2201,10 @@ static void handle_regular (struct receiver_state *rst, nn_etime_t tnow, struct
         nn_reorder_result_t rres2;
         if (wn->in_sync == PRMSS_SYNC)
           continue;
+        /* only need to get a copy of the first sample, because that's the one
+           that triggered delivery */
         if (!reuse_rsample_dup)
-          rsample_dup = nn_reorder_rsample_dup (rmsg, rsample);
+          rsample_dup = nn_reorder_rsample_dup_first (rmsg, rsample);
         rres2 = nn_reorder_rsample (&sc, wn->u.not_in_sync.reorder, rsample_dup, &refc_adjust, nn_dqueue_is_full (pwr->dqueue));
         switch (rres2)
         {