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addaleaxdeepak1556
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buffer: throw exception when creating from non-Node.js Context
Throw an exception instead of crashing when attempting to create `Buffer` objects from a Context that is not associated with a Node.js `Environment`. Possible alternatives for the future might be just returning a plain `Uint8Array`, or working on providing `Buffer` for all `Context`s. PR-URL: nodejs/node#23938 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
1 parent b2ed6c3 commit 7b35642

3 files changed

Lines changed: 38 additions & 5 deletions

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‎doc/api/errors.md‎

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@@ -613,6 +613,19 @@ An attempt was made to register something that is not a function as an
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The type of an asynchronous resource was invalid. Note that users are also able
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to define their own types if using the public embedder API.
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<a id="ERR_BUFFER_CONTEXT_NOT_AVAILABLE"></a>
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### ERR_BUFFER_CONTEXT_NOT_AVAILABLE
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An attempt was made to create a Node.js `Buffer` instance from addon or embedder
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code, while in a JS engine Context that is not associated with a Node.js
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instance. The data passed to the `Buffer` method will have been released
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by the time the method returns.
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When encountering this error, a possible alternative to creating a `Buffer`
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instance is to create a normal `Uint8Array`, which only differs in the
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prototype of the resulting object. `Uint8Array`s are generally accepted in all
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Node.js core APIs where `Buffer`s are; they are available in all Contexts.
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<a id="ERR_BUFFER_OUT_OF_BOUNDS"></a>
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### ERR_BUFFER_OUT_OF_BOUNDS
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‎src/node_buffer.cc‎

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@@ -256,7 +256,10 @@ MaybeLocal<Object> New(Isolate* isolate, size_t length) {
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EscapableHandleScope handle_scope(isolate);
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Local<Object> obj;
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Environment* env = Environment::GetCurrent(isolate);
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CHECK_NOT_NULL(env); // TODO(addaleax): Handle nullptr here.
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if (env == nullptr) {
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THROW_ERR_BUFFER_CONTEXT_NOT_AVAILABLE(isolate);
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return MaybeLocal<Object>();
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}
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if (Buffer::New(env, length).ToLocal(&obj))
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return handle_scope.Escape(obj);
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return Local<Object>();
@@ -287,7 +290,10 @@ MaybeLocal<Object> New(Environment* env, size_t length) {
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MaybeLocal<Object> Copy(Isolate* isolate, const char* data, size_t length) {
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EscapableHandleScope handle_scope(isolate);
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Environment* env = Environment::GetCurrent(isolate);
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CHECK_NOT_NULL(env); // TODO(addaleax): Handle nullptr here.
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if (env == nullptr) {
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THROW_ERR_BUFFER_CONTEXT_NOT_AVAILABLE(isolate);
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return MaybeLocal<Object>();
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}
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Local<Object> obj;
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if (Buffer::Copy(env, data, length).ToLocal(&obj))
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return handle_scope.Escape(obj);
@@ -325,7 +331,11 @@ MaybeLocal<Object> New(Isolate* isolate,
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void* hint) {
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EscapableHandleScope handle_scope(isolate);
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Environment* env = Environment::GetCurrent(isolate);
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CHECK_NOT_NULL(env); // TODO(addaleax): Handle nullptr here.
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if (env == nullptr) {
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callback(data, hint);
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THROW_ERR_BUFFER_CONTEXT_NOT_AVAILABLE(isolate);
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return MaybeLocal<Object>();
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}
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Local<Object> obj;
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if (Buffer::New(env, data, length, callback, hint).ToLocal(&obj))
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return handle_scope.Escape(obj);
@@ -365,7 +375,11 @@ MaybeLocal<Object> New(Environment* env,
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MaybeLocal<Object> New(Isolate* isolate, char* data, size_t length) {
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EscapableHandleScope handle_scope(isolate);
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Environment* env = Environment::GetCurrent(isolate);
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CHECK_NOT_NULL(env); // TODO(addaleax): Handle nullptr here.
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if (env == nullptr) {
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free(data);
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THROW_ERR_BUFFER_CONTEXT_NOT_AVAILABLE(isolate);
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return MaybeLocal<Object>();
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}
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Local<Object> obj;
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if (Buffer::New(env, data, length, true).ToLocal(&obj))
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return handle_scope.Escape(obj);

‎src/node_errors.h‎

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -17,6 +17,7 @@ namespace node {
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// a `Local<Value>` containing the TypeError with proper code and message
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#define ERRORS_WITH_CODE(V) \
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V(ERR_BUFFER_CONTEXT_NOT_AVAILABLE, Error) \
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V(ERR_BUFFER_OUT_OF_BOUNDS, RangeError) \
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V(ERR_BUFFER_TOO_LARGE, Error) \
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V(ERR_CANNOT_TRANSFER_OBJECT, TypeError) \
@@ -55,6 +56,8 @@ namespace node {
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// Errors with predefined static messages
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#define PREDEFINED_ERROR_MESSAGES(V) \
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V(ERR_BUFFER_CONTEXT_NOT_AVAILABLE, \
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"Buffer is not available for the current Context") \
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V(ERR_CANNOT_TRANSFER_OBJECT, "Cannot transfer object of unsupported type")\
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V(ERR_CLOSED_MESSAGE_PORT, "Cannot send data on closed MessagePort") \
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V(ERR_CONSTRUCT_CALL_REQUIRED, "Cannot call constructor without `new`") \
@@ -73,8 +76,11 @@ namespace node {
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inline v8::Local<v8::Value> code(v8::Isolate* isolate) { \
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return code(isolate, message); \
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} \
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inline void THROW_ ## code(v8::Isolate* isolate) { \
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isolate->ThrowException(code(isolate, message)); \
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} \
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inline void THROW_ ## code(Environment* env) { \
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env->isolate()->ThrowException(code(env->isolate(), message)); \
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THROW_ ## code(env->isolate()); \
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}
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PREDEFINED_ERROR_MESSAGES(V)
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#undef V

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