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Implement streaming decode and ignoreBOM flag for TextDecoder.
https://encoding.spec.whatwg.org/#dom-textdecoder-decodehttps://encoding.spec.whatwg.org/#dom-textdecoder-ignorebom
---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#13234 (github issue number if applicable).
- [x] These changes fix#5600 (github issue number if applicable).
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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because the wpt tests are used for testing:
* /encoding/textdecoder-fatal-streaming.html
* /encoding/textdecoder-streaming.html
* /encoding/textdecoder-ignorebom.html
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Source-Repo: https://github.com/servo/servo
Source-Revision: 1981efcc3585d244f6293716fbcf833afa58e629
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r? jdm
---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#20344 (github issue number if applicable).
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- [ ] These changes do not require tests because _____
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Source-Repo: https://github.com/servo/servo
Source-Revision: 2f94e0d2a8c79f999e64231d2dbce5582ef1a689
This might be a bad idea, especially on the webidl side. However, we started talking about the idea that modelines are a lint error (https://github.com/servo/servo/issues/10719), and these changes would be required before enabling a modeline lint.
If it bitrots, it's easy to recreate with
```
find * -type f -exec sed '/- Mode:/d' -i {} +
find * -type f -exec sed '/ vim:/d' -i {} +
git checkout -- python/tidy/servo_tidy/tidy.py
git checkout -- python/tidy/servo_tidy_tests/spec.webidl
git commit -a
```
Source-Repo: https://github.com/servo/servo
Source-Revision: dff217c2e3ff0b77eeebf62d36c2bf57c044cf14
