Fix when the reference of a TLSWrap instance is kept, but the StreamBase stream_ is free'd.

tls_wrap-isalive-bad-pointer.diff

diff --git a/src/stream_base.h b/src/stream_base.h
index faddee8..3592975 100644
--- a/src/stream_base.h
+++ b/src/stream_base.h
@@ -146,10 +146,14 @@ class StreamResource {
                          const uv_buf_t* buf,
                          uv_handle_type pending,
                          void* ctx);
+  typedef void (*DestructCb)(void* ctx);
 
   StreamResource() : bytes_read_(0) {
   }
-  virtual ~StreamResource() = default;
+  virtual ~StreamResource() {
+    if (!destruct_cb_.is_empty())
+      destruct_cb_.fn(destruct_cb_.ctx);
+  }
 
   virtual int DoShutdown(ShutdownWrap* req_wrap) = 0;
   virtual int DoTryWrite(uv_buf_t** bufs, size_t* count);
@@ -186,15 +190,18 @@ class StreamResource {
 
   inline void set_alloc_cb(Callback<AllocCb> c) { alloc_cb_ = c; }
   inline void set_read_cb(Callback<ReadCb> c) { read_cb_ = c; }
+  inline void set_destruct_cb(Callback<DestructCb> c) { destruct_cb_ = c; }
 
   inline Callback<AfterWriteCb> after_write_cb() { return after_write_cb_; }
   inline Callback<AllocCb> alloc_cb() { return alloc_cb_; }
   inline Callback<ReadCb> read_cb() { return read_cb_; }
+  inline Callback<DestructCb> destruct_cb() { return destruct_cb_; }
 
  private:
   Callback<AfterWriteCb> after_write_cb_;
   Callback<AllocCb> alloc_cb_;
   Callback<ReadCb> read_cb_;
+  Callback<DestructCb> destruct_cb_;
   uint64_t bytes_read_;
 
   friend class StreamBase;
diff --git a/src/tls_wrap.cc b/src/tls_wrap.cc
index d1b1aec..39642cf 100644
--- a/src/tls_wrap.cc
+++ b/src/tls_wrap.cc
@@ -64,6 +64,7 @@ TLSWrap::TLSWrap(Environment* env,
   stream_->set_after_write_cb({ OnAfterWriteImpl, this });
   stream_->set_alloc_cb({ OnAllocImpl, this });
   stream_->set_read_cb({ OnReadImpl, this });
+  stream_->set_destruct_cb({ OnDestructImpl, this });
 
   set_alloc_cb({ OnAllocSelf, this });
   set_read_cb({ OnReadSelf, this });
@@ -522,7 +523,7 @@ int TLSWrap::GetFD() {
 
 
 bool TLSWrap::IsAlive() {
-  return ssl_ != nullptr && stream_->IsAlive();
+  return ssl_ != nullptr && stream_ != nullptr && stream_->IsAlive();
 }
 
 
@@ -660,6 +661,12 @@ void TLSWrap::OnReadImpl(ssize_t nread,
 }
 
 
+void TLSWrap::OnDestructImpl(void* ctx) {
+  TLSWrap* wrap = static_cast<TLSWrap*>(ctx);
+  wrap->clear_stream();
+}
+
+
 void TLSWrap::OnAllocSelf(size_t suggested_size, uv_buf_t* buf, void* ctx) {
   buf->base = static_cast<char*>(node::Malloc(suggested_size));
   CHECK_NE(buf->base, nullptr);
diff --git a/src/tls_wrap.h b/src/tls_wrap.h
index f390c9f..fbf664e 100644
--- a/src/tls_wrap.h
+++ b/src/tls_wrap.h
@@ -54,6 +54,8 @@ class TLSWrap : public AsyncWrap,
 
   size_t self_size() const override { return sizeof(*this); }
 
+  void clear_stream() { stream_ = nullptr; }
+
  protected:
   static const int kClearOutChunkSize = 16384;
 
@@ -121,6 +123,7 @@ class TLSWrap : public AsyncWrap,
                          const uv_buf_t* buf,
                          uv_handle_type pending,
                          void* ctx);
+  static void OnDestructImpl(void* ctx);
 
   void DoRead(ssize_t nread, const uv_buf_t* buf, uv_handle_type pending);