Fix: Twcc wraparound uint16 promotion case

src/source/PeerConnection/PeerConnection.c

@@ -1909,7 +1909,7 @@ static STATUS twccRollingWindowDeletion(PKvsPeerConnection pKvsPeerConnection, P
         }
         // reset before next iteration
         tempTwccRtpPktInfo = NULL;
-    } while (!isCheckComplete && updatedSeqNum != (endingSeqNum + 1));
+    } while (!isCheckComplete && updatedSeqNum != (UINT16) (endingSeqNum + 1));
 
     // Update regardless. The loop checks until current RTP packets seq number irrespective of the failure
     pKvsPeerConnection->pTwccManager->firstSeqNumInRollingWindow = updatedSeqNum;

src/source/PeerConnection/Rtcp.c

@@ -344,7 +344,7 @@ STATUS updateTwccHashTable(PTwccManager pTwccManager, PINT64 duration, PUINT64 r
     // We also check for twcc->lastReportedSeqNum + 1 to include the last seq number in the
     // report. Without this, we do not check for the seqNum that could cause it to not be cleared
     // from memory
-    for (seqNum = baseSeqNum; seqNum != (pTwccManager->lastReportedSeqNum + 1); seqNum++) {
+    for (seqNum = baseSeqNum; seqNum != (UINT16) (pTwccManager->lastReportedSeqNum + 1); seqNum++) {
         if (!localStartTimeRecorded) {
             // This could happen if the prev packet was deleted as part of rolling window or if there
             // is an overlap of RTP packet statuses between TWCC packets. This could also fail if it is

tst/RtcpFunctionalityTest.cpp

@@ -471,6 +471,44 @@ TEST_F(RtcpFunctionalityTest, updateTwccHashTableTest)
     EXPECT_EQ(STATUS_SUCCESS, freePeerConnection(&pRtcPeerConnection));
 }
 
+TEST_F(RtcpFunctionalityTest, updateTwccHashTableIntPromotionCase) {
+    PRtcPeerConnection pRtcPeerConnection = NULL;
+    PKvsPeerConnection pKvsPeerConnection = NULL;
+    RtcConfiguration config{};
+    EXPECT_EQ(STATUS_SUCCESS, createPeerConnection(&config, &pRtcPeerConnection));
+    pKvsPeerConnection = reinterpret_cast<PKvsPeerConnection>(pRtcPeerConnection);
+    PTwccRtpPacketInfo pTwccRtpPacketInfo = NULL;
+    INT64 duration = 0;
+    UINT64 receivedBytes = 0, receivedPackets = 0, sentBytes = 0, sentPackets = 0;
+    UINT16 i;
+
+    // Grab the hash table
+    PHashTable pTwccRtpPktInfosHashTable = pKvsPeerConnection->pTwccManager->pTwccRtpPktInfosHashTable;
+    UINT16 hashTableInsertionCount = 0;
+
+    // Set up the hash table
+    pKvsPeerConnection->pTwccManager->prevReportedBaseSeqNum = UINT16_MAX;
+    pKvsPeerConnection->pTwccManager->lastReportedSeqNum = UINT16_MAX;
+
+    // Add packet at UINT16_MAX
+    pTwccRtpPacketInfo = (PTwccRtpPacketInfo) MEMCALLOC(1, SIZEOF(TwccRtpPacketInfo));
+    EXPECT_EQ(STATUS_SUCCESS, hashTableUpsert(pTwccRtpPktInfosHashTable, UINT16_MAX, (UINT64) pTwccRtpPacketInfo));
+    hashTableInsertionCount++;
+
+    // Even though pTwccManager->lastReportedSeqNum is a UINT16, (pTwccManager->lastReportedSeqNum + 1) can get
+    // promoted to an int (32) when pTwccManager->lastReportedSeqNum == UINT16_MAX
+    EXPECT_EQ(STATUS_SUCCESS, updateTwccHashTable(pKvsPeerConnection->pTwccManager, &duration,
+                                                  &receivedBytes, &receivedPackets,
+                                                  &sentBytes, &sentPackets));
+
+    EXPECT_EQ(0, pTwccRtpPktInfosHashTable->itemCount);  // Ensure the table is cleared again
+
+    MUTEX_LOCK(pKvsPeerConnection->twccLock);
+    MUTEX_UNLOCK(pKvsPeerConnection->twccLock);
+
+    EXPECT_EQ(STATUS_SUCCESS, freePeerConnection(&pRtcPeerConnection));
+}
+
 } // namespace webrtcclient
 } // namespace video
 } // namespace kinesis