PSync: use interest lifetime as initialRto in SegmentFetcher

refs: #4945

Change-Id: If9e3d268da3dbffda3f4a7d67039413954628d2b
diff --git a/tests/test-full-producer.cpp b/tests/test-full-producer.cpp
index 8190446..2bd7db4 100644
--- a/tests/test-full-producer.cpp
+++ b/tests/test-full-producer.cpp
@@ -18,6 +18,7 @@
  **/
 
 #include "PSync/full-producer.hpp"
+#include "unit-test-time-fixture.hpp"
 
 #include <boost/test/unit_test.hpp>
 #include <ndn-cxx/name.hpp>
@@ -50,6 +51,20 @@
   BOOST_REQUIRE_NO_THROW(node.onSyncInterest(syncPrefix, Interest(syncInterestName)));
 }
 
+BOOST_FIXTURE_TEST_CASE(ConstantTimeoutForFirstSegment, ndn::tests::UnitTestTimeFixture)
+{
+  Name syncPrefix("/psync"), userNode("/testUser");
+  util::DummyClientFace face(io, {true, true});
+
+  FullProducer node(40, face, syncPrefix, userNode, nullptr, ndn::time::milliseconds(8000));
+  advanceClocks(ndn::time::milliseconds(10));
+  face.sentInterests.clear();
+
+  // full sync sends the next one in interest lifetime / 2 +- jitter
+  advanceClocks(ndn::time::milliseconds(6000));
+  BOOST_CHECK_EQUAL(face.sentInterests.size(), 1);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 } // namespace psync
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