data_transfer: avoid double free on shutdown

GitLab: #943
Change-Id: I6f011053278bd2d3016e390c281f1cf47dfeac79

src/data_transfer.cpp

@@ -167,8 +167,11 @@ IncomingFile::~IncomingFile()
 {
     if (channel_)
         channel_->setOnRecv({});
+    {
+        std::lock_guard<std::mutex> lk(streamMtx_);
         if (stream_ && stream_.is_open())
             stream_.close();
+    }
     if (channel_)
         channel_->shutdown();
 }
@@ -187,6 +190,7 @@ IncomingFile::process()
 {
     channel_->setOnRecv([w = weak()](const uint8_t* buf, size_t len) {
         if (auto shared = w.lock()) {
+            // No need to lock, setOnRecv is resetted before closing
             if (shared->stream_.is_open())
                 shared->stream_.write(reinterpret_cast<const char*>(buf), len);
             shared->info_.bytesProgress = shared->stream_.tellp();
@@ -197,8 +201,11 @@ IncomingFile::process()
         auto shared = w.lock();
         if (!shared)
             return;
+        {
+            std::lock_guard<std::mutex> lk(shared->streamMtx_);
             if (shared->stream_ && shared->stream_.is_open())
                 shared->stream_.close();
+        }
         auto correct = shared->sha3Sum_.empty();
         if (!correct) {
             // Verify shaSum

src/data_transfer.h

@@ -97,6 +97,7 @@ private:
     {
         return std::static_pointer_cast<IncomingFile>(shared_from_this());
     }
+    std::mutex streamMtx_;
     std::ofstream stream_;
     std::string sha3Sum_ {};
 };