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[18.8.0] char* node::Buffer::Data(v8::Local<v8::Object> val) returns a NULL pointer when given a valid v8::Object #44554
Description
Activity
/cc @nodejs/cpp-reviewers @kvakil. This seems caused by 8c35a4e#diff-81f77f34c4f5b8cc35f1a506808b94e2a281f3341c0f1a38ef2b8a8ba730b22bL247 ?
I suspect the problem is here: it calls
Nan::NewBuffer()withlength == 0.Maybe that worked before but it's basically saying "this is an empty buffer" and those don't have to point to anything.
Thanks @targos for the bisect. I've confirmed Ben's comment that this is an edge case with zero-length buffers: if you bump the "length" in
WrapPointerfrom 0 to 1, then everything works. I am a little ambivalent about fixing the issue, but a codesearch did reveal several repos which are using this pattern, so I think we should just revert.A fix is available here; #44579
Reacted by corentingurtner- added a commit that references this issue
on Sep 12, 2022 This issue has been marked as stale due to 210 days of inactivity.
It will be automatically closed in 30 days if no further activity occurs. If this is still relevant, please leave a comment or update it to keep it open.This issue has been automatically closed after 30 days of inactivity following its stale status (no activity for a total of 120 days).
If this is still relevant, feel free to reopen it or leave a comment with additional details so we can continue the discussion.
Version
18.8.0
Platform
macOS Monterey 12.4
Subsystem
No response
What steps will reproduce the bug?
Try to initialise a lame Encoder using this lib : https://github.com/FlatIO/node-lame (check Example : https://github.com/FlatIO/node-lame#example)
How often does it reproduce? Is there a required condition?
Everytime
What is the expected behavior?
node::Buffer::Data()returns a valid pointer when a valid v8::Object is provided.Then, the lame Encoder is initialized without any issue.
What do you see instead?
node::Buffer::Data()returns a NULL pointer.The lame encoder returns this error: “error setting prop “channels”: -1"
Additional information
This was working fine with node v18.7.0 and all the previous versions so this is very probably an issue with Node.
I did some investigation and found out that it was caused by a NULL pointer returned by
node::Buffer::Data()when provided with a seemingly validv8::ObjectI tested the
v8::Objectwith->IsObject(), it returned true, and with->IsNullOrUndefined()and it returned false;The
v8::Object(GFP) represents Lame global flags, andnode::Buffer::Datais used to unwrap the pointer after sending it through a JS binding