FA-75773 / Text diff and three-way merge / Member archive

Tree listing diff: an executable-bit change is reported as a type change · case 03

Toggling the executable bit shows up as "T" instead of a modification.

Member previewVariant 3 · 3 implementations · 9 checks per implementation

Case contract

Compare two tree listings of [name, mode, hash]. Entries are ordered by name, with directories (mode 040000) compared as name + "/". Walk both in that order: entries only in the old tree are "D", only in the new tree "A". Entries matched by sort key report "T" when the mode type (first two digits) differs, else "M" when the hash or mode differs. Return [status, name] rows.

Why this case matters

Tree diffs drive status, rename detection and checkout; their ordering and type-change rules follow the object-store conventions.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
exec bit change is a modification	`[["T", "run.sh"]]`	`[["M", "run.sh"]]`	Failed

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