Fix byteOffset for detached array buffers#418
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bellard merged 2 commits intoJun 14, 2025
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The spec [1] expects to read `byteOffset` even for detached buffers. Noticed a new test262 test [2] failed and there an an existing one we skipped as well for the same reason. [1] https://tc39.es/ecma262/#sec-%typedarray%.prototype.subarray [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js Fix: bellard#417
``` E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing? Error: Process completed with exit code 100. ``` As the error suggests `apt update` seems to fix it
nickva
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Previously, in issue bellard#418 and pr bellard#417 I misread the spec that in `subarray` we should be able to access the `byteOffset` from a detached buffer. Thinking more about it, something didn't seem right and I started a discussion in the TC39 group [1]. It turns out we shouldn't be able to read the ``byteOffset`` from detched buffers. Instead, the spec says we should just read the `byteOffset` value before we access `start` and `finish`. In the test262 test [2] the buffer is detached when accessing the `end` inside the `valueOf()` conversion, and the test expects to see the `byteOffset` before it was detached. So to fix it, ensure we access and save the `byteOffset` value first, then get the `start` and `finish`. [1] https://es.discourse.group/t/typedarray-subarray-byteoffset-with-detached-buffers/2381 [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js
nickva
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Previously, in issue bellard#418 and pr bellard#417 I misread the spec that in `subarray` we should be able to access the `byteOffset` from a detached buffer. Thinking more about it, something didn't seem right and I started a discussion in the TC39 group [1]. It turns out we shouldn't be able to read the ``byteOffset`` from detched buffers. Instead, the spec says we should just read the `byteOffset` value before we access `start` and `finish`. In the test262 test [2] the buffer is detached when accessing the `end` inside the `valueOf()` conversion, and the test expects to see the `byteOffset` before it was detached. So to fix it, ensure we access and save the `byteOffset` value first, then get the `start` and `finish`. [1] https://es.discourse.group/t/typedarray-subarray-byteoffset-with-detached-buffers/2381 [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js
nickva
added a commit
to nickva/quickjs
that referenced
this pull request
Jun 29, 2025
Previously, in issue bellard#418 and pr bellard#417 I misread the spec that in `subarray` we should be able to access the `byteOffset` from a detached buffer. Thinking more about it, something didn't seem right and I started a discussion in the TC39 group [1]. It turns out we shouldn't be able to read the ``byteOffset`` from detched buffers. Instead, the spec says we should just read the `byteOffset` value before we access `start` and `finish`. In the test262 test [2] the buffer is detached when accessing the `end` inside the `valueOf()` conversion, and the test expects to see the `byteOffset` before it was detached. So to fix it, ensure we access and save the `byteOffset` value first, then get the `start` and `finish`. [1] https://es.discourse.group/t/typedarray-subarray-byteoffset-with-detached-buffers/2381 [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js
nickva
added a commit
to nickva/quickjs
that referenced
this pull request
Jun 29, 2025
Previously, in issue bellard#418 and pr bellard#417 I misread the spec that in `subarray` we should be able to access the `byteOffset` from a detached buffer. Thinking more about it, something didn't seem right and I started a discussion in the TC39 group [1]. It turns out we shouldn't be able to read the ``byteOffset`` from detched buffers. Instead, the spec says we should just read the `byteOffset` value before we access `start` and `finish`. In the test262 test [2] the buffer is detached when accessing the `end` inside the `valueOf()` conversion, and the test expects to see the `byteOffset` before it was detached. So to fix it, ensure we access and save the `byteOffset` value first, then get the `start` and `finish`. [1] https://es.discourse.group/t/typedarray-subarray-byteoffset-with-detached-buffers/2381 [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js
nickva
added a commit
to nickva/quickjs
that referenced
this pull request
Jun 29, 2025
Previously, in issue bellard#418 and pr bellard#417 I misread the spec that in `subarray` we should be able to access the `byteOffset` from a detached buffer. Thinking more about it, something didn't seem right and I started a discussion in the TC39 group [1]. It turns out we shouldn't be able to read the ``byteOffset`` from detched buffers. Instead, the spec says we should just read the `byteOffset` value before we access `start` and `finish`. In the test262 test [2] the buffer is detached when accessing the `end` inside the `valueOf()` conversion, and the test expects to see the `byteOffset` before it was detached. So to fix it, ensure we access and save the `byteOffset` value first, then get the `start` and `finish`. [1] https://es.discourse.group/t/typedarray-subarray-byteoffset-with-detached-buffers/2381 [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js
nickva
added a commit
to nickva/quickjs
that referenced
this pull request
Jun 29, 2025
Previously, in issue bellard#418 and pr bellard#417 I misread the spec that in `subarray` we should be able to access the `byteOffset` from a detached buffer. Thinking more about it, something didn't seem right and I started a discussion in the TC39 group [1]. It turns out we shouldn't be able to read the ``byteOffset`` from detched buffers. Instead, the spec says we should just read the `byteOffset` value before we access `start` and `finish`. In the test262 test [2] the buffer is detached when accessing the `end` inside the `valueOf()` conversion, and the test expects to see the `byteOffset` before it was detached. So to fix it, ensure we access and save the `byteOffset` value first, then get the `start` and `finish`. [1] https://es.discourse.group/t/typedarray-subarray-byteoffset-with-detached-buffers/2381 [2] https://github.com/tc39/test262/blob/main/test/built-ins/TypedArray/prototype/subarray/byteoffset-with-detached-buffer.js
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Read byteOffset for detached buffers
The spec expects to read
byteOffseteven for detached buffers.Noticed a new test262 test failed and there is an existing one we skipped as well for the same reason.
Fix: #417