FA-75804 / Text diff and three-way merge / Member archive

Hunk function context: underscore and dollar headings are ignored · case 04

Hunks inside labels or macros that start with "_" or "$" show an older heading.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

For each hunk whose old range starts at 1-based line s, search the old lines strictly before s, nearest first, for a line whose first character is a letter, "_" or "$". The heading is that line with trailing whitespace removed, truncated to limit characters; "" if none.

Why this case matters

The text after the @@ header helps reviewers locate a hunk; choosing the wrong line or including the hunk itself misleads.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
dollar and underscore headings	`["int main(void)", "int main(void)"]`	`["$macro", "_private:"]`	Failed

MEMBER ARCHIVE

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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