src: plug memory leaks

In a few places dynamic memory was passed to the Buffer::New() overload
that makes a copy of the input, not the one that takes ownership.

This commit is a band-aid to fix the memory leaks.  Longer term, we
should look into using C++11 move semantics more effectively.

Fixes: https://github.com/nodejs/node/issues/2308
PR-URL: https://github.com/nodejs/node/pull/2352
Reviewed-By: Fedor Indutny <fedor@indutny.com>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/node_buffer.h b/src/node_buffer.h
index 5b935b8c063..f7c88f60e03 100644
--- a/src/node_buffer.h
+++ b/src/node_buffer.h
@@ -67,12 +67,17 @@ static inline bool IsWithinBounds(size_t off, size_t len, size_t max) {
 // in src/node_internals.h because of a circular dependency.
 #if defined(NODE_WANT_INTERNALS)
 v8::MaybeLocal<v8::Object> New(Environment* env, size_t size);
+// Makes a copy of |data|.
 v8::MaybeLocal<v8::Object> New(Environment* env, const char* data, size_t len);
+// Takes ownership of |data|.
 v8::MaybeLocal<v8::Object> New(Environment* env,
                                char* data,
                                size_t length,
                                FreeCallback callback,
                                void* hint);
+// Takes ownership of |data|.  Must allocate |data| with malloc() or realloc()
+// because ArrayBufferAllocator::Free() deallocates it again with free().
+// Mixing operator new and free() is undefined behavior so don't do that.
 v8::MaybeLocal<v8::Object> Use(Environment* env, char* data, size_t length);
 #endif  // defined(NODE_WANT_INTERNALS)