fix(ext/node): fix Buffer.concat truncating buffers larger than 4GB#32913
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bartlomieju merged 1 commit intomainfrom Mar 23, 2026
Merged
fix(ext/node): fix Buffer.concat truncating buffers larger than 4GB#32913bartlomieju merged 1 commit intomainfrom
bartlomieju merged 1 commit intomainfrom
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The `checked()` function and `_allocUnsafe()` used `| 0` to truncate lengths to integers, which converts numbers to 32-bit signed integers. This caused any buffer size > 2^32 to wrap around (e.g. `(2**32 + 5) | 0` becomes `5`). Replace `| 0` with `MathTrunc()` to support large buffers. Closes #32895 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
| 0(32-bit integer truncation) withMathTrunc()inchecked(),_allocUnsafe(), andfromString()in the Node.js Buffer polyfillBuffer.concatandBuffer.allocUnsafesilently truncating buffers with sizes exceeding 2^32 (e.g.(2**32 + 5) | 0→5)Closes #32895
Test plan
Buffer.allocUnsafeandBuffer.concatwith >4GB sizes (markedignore: truedue to memory requirements)./x test-node buffer)🤖 Generated with Claude Code