FA-27089 / HTTP ranges / Member archive
A proxy coalesces nearby requested spans into economical origin reads: empty selectors retain a null slot in caller mapping · case 04
A proxy coalesces nearby requested spans into economical origin reads: empty selectors retain a null slot in caller mapping.
Case contract
x contains request rows [start,stop] with half-open nonnegative bounds, a nonnegative max-gap, and a set of forbidden byte positions. Empty requests contribute no work. Sort requests by start/stop, merge overlapping or nearby reads only if the gap has no forbidden byte. Return fetch spans and, in original request order, [fetch-index,offset-within-fetch,count] mappings. Empty requests map to null. This model plans origin reads only and does not redefine inclusive wire range semantics.
Why this case matters
Range responses combine representation identity, conditional requests, framing, and partial-object state.
One recorded failure
Sample boundary fixtureThis sample comes from the broken implementation of a controlled reproducer.
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| empty-mapping fixture 4 | [[], []] | [[], [null, null]] | Failed |
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