fix: don't crash when nativeImage.createFromBuffer() is called with invalid buffer

[miniak]

Description of Change

Adds missing node::Buffer::HasInstance(buffer) check before using the buffer.

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Fixed crash when nativeImage.createFromBuffer() is called with invalid buffer.

[nornagon]

Is there a more idiomatic way of saying "get the first argument as a buffer"? I see e.g. https://github.com/electron/electron/blob/master/atom/common/native_mate_converters/v8_value_converter.cc#L245

[miniak]

@nornagon I've seen this in other APIs to validate if an instance is a Buffer

void Clipboard::WriteBuffer(const std::string& format,
                            const v8::Local<v8::Value> buffer,
                            mate::Arguments* args) {
  if (!node::Buffer::HasInstance(buffer)) {
    args->ThrowError("buffer must be a node Buffer");
    return;
  }
...
}

An abstraction could be created, but we have to make sure it does not copy the data unnecessarily.

[miniak]

@nornagon gsl::span<gsl::byte> would be a perfect abstraction for the Buffer data/size that can be parsed by mate converters. see https://github.com/Microsoft/GSL.

gsl::not_null<T> is also a nice (zero overhead in release mode) abstraction.

[release-clerk]

Release Notes Persisted

Fixed crash when nativeImage.createFromBuffer() is called with invalid buffer.

[trop]

I have automatically backported this PR to "3-1-x", please check out #17372

[trop]

I have automatically backported this PR to "4-0-x", please check out #17373

[trop]

I have automatically backported this PR to "5-0-x", please check out #17374