Function parse_unified_diff 

pub fn parse_unified_diff(diff_text: &str) -> Vec<Hunk>

Parse the output of git diff --unified=N into hunks.

Tolerant by design: anything it does not recognise is skipped rather than erroring, because a diff that cannot be parsed must not take the gate down. The intentional quirks:

• The file path comes from +++ b/…, never from diff --git a/… b/…. The git header carries two paths on one line with no unambiguous separator, so any “find b/” rule captures the wrong span for a repository path that itself contains b/ (src/b/mod.rs). The Python diff_parser.py this replaces had exactly that bug.
• +++ /dev/null marks a deletion; there is nothing to analyze, so the file’s hunks are dropped.
• Inside a hunk body the first byte alone decides the line kind. Lines starting --- or +++ are not additionally skipped: those headers appear only before the first @@ of a file, and a removed source line whose own text begins with -- arrives as ---…. Skipping it silently drops real removed code — the second bug in the Python.
• \ No newline at end of file refers to the preceding line and never becomes a HunkLine.
• A malformed @@ terminates the current hunk without its body being attributed to the previous one.