fix: replace unsafe byte indexing in parse_value with .get() + error return#45
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nathanjmcdougall merged 2 commits intoMay 25, 2026
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Pull request overview
This PR prevents a potential Rust panic (and resulting Python process crash) in PyDocument::parse_value by replacing direct UTF-8 string byte slicing with safe .get(..) range access that returns a recoverable PyValueError when spans are invalid.
Changes:
- Replaced
&source[span.0..span.1]withsource.get(span.0..span.1).ok_or_else(...)?to avoid panics on invalid UTF-8 boundaries/out-of-range spans. - Replaced
source[..span.0]with a safe.get(..span.0)-based prefix extraction before computingline_start.
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Direct byte indexing (source[span.0..span.1] and source[..span.0]) panics if yamlpath returns a span misaligned to UTF-8 boundaries, crashing the Python process. Replace with upfront is_char_boundary + bounds checks that return a recoverable error, then use direct indexing safely. Applied consistently to all 5 sites in document.rs: parse_value, apply_insert_at, and apply_complex_replace. Closes #44
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…dexing-in-parse_value-can-panic-instead-of-returning-error # Conflicts: # src/document.rs
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Direct byte indexing (source[span.0..span.1] and source[..span.0]) panics if yamlpath returns a span misaligned to UTF-8 boundaries, crashing the Python process. Replace with .get() to return a recoverable PyValueError, matching the existing safe pattern in extract().
Closes #44