WinTLS: Fix hang because of buffered received data

WinTLSSession buffers received decrypted data into its own buffer.  If
read is requested, it copies the data from its buffer.  But if
requested buffer size is less than decrypted buffer, some of the data
is left in the buffer.  Previously, we had no facility to check the
existence of this pending data.  If this data is the last requested
data from remote server, we may end up waiting for read event even if
we have already data in our buffer, which may cause hang.  This commit
fixes this issue by introducing function to return the buffered length
in TLSSession.  SocketCore also provides the same function, which
delegates to TLSSession object.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/AbstractCommand.cc b/src/AbstractCommand.cc
index 27762cc8..c2ead096 100644
--- a/src/AbstractCommand.cc
+++ b/src/AbstractCommand.cc
@@ -148,6 +148,10 @@ bool AbstractCommand::shouldProcess() const
     if (socketRecvBuffer_ && !socketRecvBuffer_->bufferEmpty()) {
       return true;
     }
+
+    if (socket_ && socket_->getRecvBufferedLength()) {
+      return true;
+    }
   }
 
   if (checkSocketIsWritable_ && writeEventEnabled()) {
@@ -916,7 +920,8 @@ const std::shared_ptr<PieceStorage>& AbstractCommand::getPieceStorage() const
 
 void AbstractCommand::checkSocketRecvBuffer()
 {
-  if (socketRecvBuffer_->bufferEmpty()) {
+  if (socketRecvBuffer_->bufferEmpty() &&
+      socket_->getRecvBufferedLength() == 0) {
     return;
   }