dualfroz
c6a4588fb3
Image height was validated against 0..=144, the same bound as width, but the RSS 2.0 specification allows heights up to 400 (width max is 144). Spec-valid images with a height between 145 and 400 were wrongly reported as invalid. Validate height against 0..=400 and fix the error message.
89 lines
2.6 KiB
Markdown
89 lines
2.6 KiB
Markdown
# Fix image height validation to allow the spec maximum of 400
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## Problem
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`Channel`/`Image` validation rejects images whose `<height>` is greater than
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144, even though the RSS 2.0 specification allows heights up to 400. A
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perfectly spec-compliant image is reported as invalid:
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```rust
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use rss::validation::Validate;
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use rss::ImageBuilder;
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let image = ImageBuilder::default()
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.url("https://example.com/image.png".to_string())
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.link("https://example.com/".to_string())
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.title("title".to_string())
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.height("200".to_string()) // valid per the RSS spec
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.build();
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assert!(image.validate().is_err()); // <- wrongly errors today
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```
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## Root cause
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`src/validation.rs`, in `impl Validate for Image`, validated `height` against
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the same range used for `width`:
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```rust
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let height = height.parse::<i64>()?;
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validate!(
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(0..=144).contains(&height),
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"Image height is not between 0 and 144"
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);
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```
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The RSS 2.0 specification (<https://www.rssboard.org/rss-specification>,
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`<image>` sub-element) states:
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- width: "Maximum value for width is 144, default value is 88."
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- height: "Maximum value for height is 400, default value is 31."
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So 144 is correct for `width`, but `height` must allow up to 400. The bound
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(and the error message) were copied from the width check.
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## Fix
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Validate `height` against `0..=400` and correct the error message:
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```rust
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let height = height.parse::<i64>()?;
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validate!(
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(0..=400).contains(&height),
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"Image height is not between 0 and 400"
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);
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```
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`width` is unchanged and keeps its specification maximum of 144.
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## Test
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Added `tests/validation.rs` (gated on the `validation` feature):
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- `image_height_allows_up_to_400`: heights 31, 200 and 400 validate OK.
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- `image_height_above_400_is_invalid`: height 401 is rejected.
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- `image_width_max_is_still_144`: width 144 is OK, 145 is rejected.
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## Gate
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- `cargo test --all-features` -> ok (all suites pass, exit 0)
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- `cargo build --all-features` -> ok (exit 0)
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- `cargo fmt --check` -> ok (exit 0)
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## Counterfactual
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Reverting the bound back to `0..=144` makes the new test fail:
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```
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thread 'image_height_allows_up_to_400' panicked at tests/validation.rs:28:5:
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assertion failed: image_with_height("200").validate().is_ok()
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```
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## Flags for the account owner
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`cargo clippy --all-targets --all-features -- -D warnings` currently fails, but
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this is pre-existing and unrelated to this change: on an unmodified checkout the
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same lint (`clippy::get_first`, i.e. "accessing first element with `.get(0)`",
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emitted by a newer Clippy than the tests were written against) already produces
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these errors in `tests/read.rs`. The files touched here are clippy-clean.
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