From 6ef674f22cfac6556db0d6e4b5d0268eba71d14f Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Sun, 30 Apr 2017 01:48:37 +0200
Subject: [PATCH] src: turn buffer type-CHECK into exception

Turn a `CHECK()` that could be brought to fail using public APIs
into throwing an error.

Fixes: https://github.com/nodejs/node/issues/12152
---
 src/stream_base.cc                             | 7 ++++++-
 test/parallel/test-stream-base-typechecking.js | 7 +++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-stream-base-typechecking.js

diff --git a/src/stream_base.cc b/src/stream_base.cc
index 3ed622d7ef35a2..19130b5bb8bd7e 100644
--- a/src/stream_base.cc
+++ b/src/stream_base.cc
@@ -189,9 +189,14 @@ int StreamBase::Writev(const FunctionCallbackInfo<Value>& args) {
 
 int StreamBase::WriteBuffer(const FunctionCallbackInfo<Value>& args) {
   CHECK(args[0]->IsObject());
-  CHECK(Buffer::HasInstance(args[1]));
+
   Environment* env = Environment::GetCurrent(args);
 
+  if (!args[1]->IsUint8Array()) {
+    env->ThrowTypeError("Second argument must be a buffer");
+    return 0;
+  }
+
   Local<Object> req_wrap_obj = args[0].As<Object>();
   const char* data = Buffer::Data(args[1]);
   size_t length = Buffer::Length(args[1]);
diff --git a/test/parallel/test-stream-base-typechecking.js b/test/parallel/test-stream-base-typechecking.js
new file mode 100644
index 00000000000000..d1b8bfc699c845
--- /dev/null
+++ b/test/parallel/test-stream-base-typechecking.js
@@ -0,0 +1,7 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+assert.throws(() => {
+  process.stdout.write('broken', 'buffer');
+}, /^TypeError: Second argument must be a buffer$/);