From 4a3da5fa881a24ecd85599d4fb714ad56b908000 Mon Sep 17 00:00:00 2001
From: David Herman <david.herman@gmail.com>
Date: Wed, 11 Jul 2018 16:50:47 -0700
Subject: [PATCH] `JsBuffer::new()` always produces a zeroed buffer.
 `JsBuffer::uninitialized()` produces a non-zero-filled buffer but is marked
 `unsafe`.

---
 crates/neon-runtime/src/buffer.rs |  7 ++++++-
 crates/neon-runtime/src/neon.cc   | 11 +++++++++++
 crates/neon-runtime/src/neon.h    |  1 +
 src/value/binary.rs               |  7 ++++++-
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/crates/neon-runtime/src/buffer.rs b/crates/neon-runtime/src/buffer.rs
index 71ecf56a2..ede808537 100644
--- a/crates/neon-runtime/src/buffer.rs
+++ b/crates/neon-runtime/src/buffer.rs
@@ -5,11 +5,16 @@ use std::os::raw::c_void;
 
 extern "C" {
 
-    /// Mutates the `out` argument provided to refer to a newly created `node::Buffer` object.
+    /// Mutates the `out` argument provided to refer to a newly created and zero-filled `node::Buffer` object.
     /// Returns `false` if the value couldn't be created.
     #[link_name = "Neon_Buffer_New"]
     pub fn new(out: &mut Local, size: u32) -> bool;
 
+    /// Mutates the `out` argument provided to refer to a newly created `node::Buffer` object.
+    /// Returns `false` if the value couldn't be created.
+    #[link_name = "Neon_Buffer_Uninitialized"]
+    pub fn uninitialized(out: &mut Local, size: u32) -> bool;
+
     /// Mutates the `base_out` and `size_out` arguments to access the data of a `node::Buffer` object.
     #[link_name = "Neon_Buffer_Data"]
     pub fn data<'a, 'b>(base_out: &'a mut *mut c_void, size_out: &'a mut usize, obj: Local);
diff --git a/crates/neon-runtime/src/neon.cc b/crates/neon-runtime/src/neon.cc
index e433c3e58..63b2f350d 100644
--- a/crates/neon-runtime/src/neon.cc
+++ b/crates/neon-runtime/src/neon.cc
@@ -178,6 +178,17 @@ extern "C" bool Neon_Convert_ToObject(v8::Local<v8::Object> *out, v8::Local<v8::
 }
 
 extern "C" bool Neon_Buffer_New(v8::Local<v8::Object> *out, uint32_t size) {
+  Nan::MaybeLocal<v8::Object> maybe = Nan::NewBuffer(size);
+  if (!maybe.ToLocal(out)) {
+    return false;
+  }
+
+  void *data = node::Buffer::Data(*out);
+  memset(data, 0, size);
+  return true;
+}
+
+extern "C" bool Neon_Buffer_Uninitialized(v8::Local<v8::Object> *out, uint32_t size) {
   Nan::MaybeLocal<v8::Object> maybe = Nan::NewBuffer(size);
   return maybe.ToLocal(out);
 }
diff --git a/crates/neon-runtime/src/neon.h b/crates/neon-runtime/src/neon.h
index f032e9327..f84775b22 100644
--- a/crates/neon-runtime/src/neon.h
+++ b/crates/neon-runtime/src/neon.h
@@ -53,6 +53,7 @@ extern "C" {
   void Neon_Buffer_Data(void **base_out, size_t *len_out, v8::Local<v8::Object> obj);
 
   bool Neon_ArrayBuffer_New(v8::Local<v8::ArrayBuffer> *out, v8::Isolate *isolate, uint32_t size);
+  bool Neon_ArrayBuffer_Uninitialized(v8::Local<v8::ArrayBuffer> *out, v8::Isolate *isolate, uint32_t size);
   void Neon_ArrayBuffer_Data(void **base_out, size_t *len_out, v8::Local<v8::ArrayBuffer> buffer);
 
   typedef void(*Neon_ChainedScopeCallback)(void *, void *, void *, void *);
diff --git a/src/value/binary.rs b/src/value/binary.rs
index f76707d7b..72afa4148 100644
--- a/src/value/binary.rs
+++ b/src/value/binary.rs
@@ -20,11 +20,16 @@ pub struct JsBuffer(raw::Local);
 
 impl JsBuffer {
 
-    /// Constructs a new `Buffer` object.
+    /// Constructs a new `Buffer` object, safely zero-filled.
     pub fn new<'a, C: Context<'a>>(_: &mut C, size: u32) -> JsResult<'a, JsBuffer> {
         build(|out| { unsafe { neon_runtime::buffer::new(out, size) } })
     }
 
+    /// Constructs a new `Buffer` object, safely zero-filled.
+    pub unsafe fn uninitialized<'a, C: Context<'a>>(_: &mut C, size: u32) -> JsResult<'a, JsBuffer> {
+        build(|out| { neon_runtime::buffer::uninitialized(out, size) })
+    }
+
 }
 
 impl Managed for JsBuffer {