From 56e1491f8bab304dcd91b3eba31c35427f3a51fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Javier=20Cervi=C3=B1o?= <jcague@gmail.com>
Date: Wed, 1 Mar 2017 09:18:49 +0100
Subject: [PATCH] Fix several loops in SequenceNumberTranslator (#784)

---
 .../erizo/rtp/SequenceNumberTranslator.cpp    |  2 +-
 .../test/rtp/SequenceNumberTranslatorTest.cpp | 30 +++++++++----------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/erizo/src/erizo/rtp/SequenceNumberTranslator.cpp b/erizo/src/erizo/rtp/SequenceNumberTranslator.cpp
index f2d091c95c..82eea4fbed 100644
--- a/erizo/src/erizo/rtp/SequenceNumberTranslator.cpp
+++ b/erizo/src/erizo/rtp/SequenceNumberTranslator.cpp
@@ -84,7 +84,7 @@ SequenceNumber SequenceNumberTranslator::get(uint16_t input_sequence_number, boo
 
     add(SequenceNumber{input_sequence_number, output_sequence_number, type});
     last_input_sequence_number_ = input_sequence_number;
-    if (last_input_sequence_number_ - kMaxDistance > first_input_sequence_number_) {
+    if (RtpUtils::sequenceNumberLessThan(first_input_sequence_number_, last_input_sequence_number_ - kMaxDistance)) {
       first_input_sequence_number_ = last_input_sequence_number_ - kMaxDistance;
     }
     SequenceNumber info = get(input_sequence_number);
diff --git a/erizo/src/test/rtp/SequenceNumberTranslatorTest.cpp b/erizo/src/test/rtp/SequenceNumberTranslatorTest.cpp
index b7fb977e8b..7f679c53bf 100644
--- a/erizo/src/test/rtp/SequenceNumberTranslatorTest.cpp
+++ b/erizo/src/test/rtp/SequenceNumberTranslatorTest.cpp
@@ -57,24 +57,21 @@ TEST_P(SequenceNumberTranslatorTest, shouldReturnRightOutputSequenceNumbers) {
     SequenceNumber output = translator.get(packet.sequence_number, skip);
     EXPECT_THAT(output.output, Eq(packet.expected_output));
     EXPECT_THAT(output.type, Eq(packet.expected_type));
-  }
-}
 
-TEST_P(SequenceNumberTranslatorTest, shouldReturnRightInputSequenceNumbers) {
-  for (Packet packet : queue) {
-    bool skip = packet.state == PacketState::Skip;
-    translator.get(packet.sequence_number, skip);
+    translator.reverse(packet.expected_output);
+    ASSERT_THAT(output.input, Eq(packet.sequence_number));
+    ASSERT_THAT(output.type, Eq(packet.expected_type));
   }
+}
 
-  // Reverse look-up
-  for (Packet packet : queue) {
-    if (packet.expected_type != SequenceNumberType::Valid) {
-      continue;
-    }
-    SequenceNumber output = translator.reverse(packet.expected_output);
-    EXPECT_THAT(output.input, Eq(packet.sequence_number));
-    EXPECT_THAT(output.type, Eq(packet.expected_type));
+std::vector<Packet> getLongQueue(int size) {
+  std::vector<Packet> queue;
+  for (int i = 0; i <= size; i++) {
+    int input_sequence_number = i % 65535;
+    queue.push_back(Packet{input_sequence_number, PacketState::Forward,
+                           input_sequence_number, SequenceNumberType::Valid});
   }
+  return queue;
 }
 
 INSTANTIATE_TEST_CASE_P(
@@ -139,4 +136,7 @@ INSTANTIATE_TEST_CASE_P(
     std::vector<Packet>({{ 65535, PacketState::Forward,           65535, SequenceNumberType::Valid},
                          {     1, PacketState::Forward,               1, SequenceNumberType::Valid},
                          {     0, PacketState::Skip,                  0, SequenceNumberType::Discard},
-                         {     2, PacketState::Forward,               2, SequenceNumberType::Valid}})));
+                         {     2, PacketState::Forward,               2, SequenceNumberType::Valid}}),
+
+    // Support multiple loops
+    getLongQueue(65535 * 2)));