Rewrite UTF8Validator

[SimonSapin]

• Rename it to Utf8LossyDecoder
• Don’t allocate any memory.
• Handles errors per Unicode Standard §5.22 "Best Practice for U+FFFD Substitution" This matches String::from_utf8_lossy.

This introduces two (recursive) dependencies that should probably be reviewed as well:

• rust-utf8
• string-wrapper

r? @nox

[asajeffrey]

Reviewed 3 of 3 files at r1.
Review status: all files reviewed at latest revision, 2 unresolved discussions.

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src/stream.rs, line 46 [r1] (raw file):
Bikeshedding: should Utf8LossyDecoder and Decoder follow the same naming scheme? (That is, either Utf8LossyDecoder becomes LossyDecoder or Decoder becomes Utf8Decoder.)

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src/stream.rs, line 90 [r1] (raw file):
Add an assert! for this?

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Comments from the review on Reviewable.io

[asajeffrey]

I did a brief look over the new dependencies, and they look fine. They could both do with a LICENSE file as well as a Cargo.toml file (not all lawyers know their way around Cargo).

[SimonSapin]

I’ve pushed some more changes and used them in html5ever: servo/html5ever#188

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Review status: 0 of 5 files reviewed at latest revision, 2 unresolved discussions.

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src/stream.rs, line 46 [r1] (raw file):
I’ve renamed Decoder to LossyDecoder. The difference between the two is UTF-8 v.s. any given encoding, not lossy v.s. not.

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src/stream.rs, line 90 [r1] (raw file):
subtendril is safe: it checks that the given offset and length are within bounds and panics if they’re not. An assert would only panic earlier in the same cases.

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Comments from the review on Reviewable.io

[asajeffrey]

Reviewed 5 of 5 files at r3.
Review status: all files reviewed at latest revision, 1 unresolved discussion.

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src/fmt.rs, line 182 [r3] (raw file):
The comments for this trait talk about Format, which used to be an associated type, but has now vanished.

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Comments from the review on Reviewable.io

[asajeffrey]

@bors-servo r+

[SimonSapin]

@bors-servo r=asajeffrey

[asajeffrey]

@bors-servo r+

[SimonSapin]

Travis is not feeling well:

https://travis-ci.org/servo/tendril/jobs/104723799

Installing Rust

0.94s$ curl -sL https://static.rust-lang.org/rustup.sh -o ~/rust-installer/rustup.sh

$ sh ~/rust-installer/rustup.sh --prefix=~/rust --spec=nightly -y --disable-sudo 2> /dev/null

rustup: gpg available. signatures will be verified

rustup: downloading manifest for 'nightly'

rustup: downloading toolchain for 'nightly'

No output has been received in the last 10 minutes, this potentially indicates a stalled build or something wrong with the build itself.

The build has been terminated

I’ve run tests locally on all three Rust release channels.