nx_hashdiverge.nx

nx_hashdiverge.nx -- CONTENT-EXACT CROSS-TREE DIVERGENCE. The comparer half of nx_treehash. WHY IT EXISTS (measured 2026-08-06, tree-canon-single-writer lane): nx_treediverge compares nx_treediff manifests, which carry SIZE. Its own usage line says the verdicts are "(by BYTES, a FLOOR)" and it is right. The hourly treediverge beat therefore reported a size floor as if it were the fork, for days, and one of the files it could not see was an ESCAPED nx_gate_bite MUTANT in buildroot: _hdl_build/nx_media_extract.nx held `if hit != 0` where the SSOT held `if hit == 0` -- one byte, 4389 bytes on BOTH sides, so every plain-http: URL was silently dropped from media harvest and no size gauge could ever notice. => A MUTATION-CLASS DEFECT IS SIZE-PRESERVING BY CONSTRUCTION. A size screen is not merely approximate against it, it is STRUCTURALLY BLIND to the whole class. Of 18060 files present in both trees, only 5 differed at equal size -- and 1 of those 5 was the mutant. TWO IMPROVEMENTS OVER THE ORGAN IT SUCCEEDS, both learned by being bitten in the same session: 1. DETAIL GOES TO A FILE, ENVELOPE GOES TO STDOUT. Running nx_treediverge over these trees returned 163,936 characters and was cut off at capture_cap mid-row, so the envelope -- the only line carrying the counts -- was the part that got dropped. A comparer whose SUMMARY is the first casualty of its own verbosity cannot be wired to a beat. Rows go to [outfile]. 2. THE SAME-SIZE CLASS IS COUNTED SEPARATELY. It is the only class a size screen cannot reach, so it is the number that says whether the cheap gauge upstream is still trustworthy. CLASSES: IDENT (sha equal) / DIFFSZ (sha differs, size differs -- a size screen sees these) / SAMESZ (sha differs, size EQUAL -- the blind spot) / A-ONLY / B-ONLY. An UNREADABLE row from nx_treehash is 64 '-', which is not hex and never equals itself, so an unreadable file always classifies as divergent rather than silently matching another unreadable. DIALECT: plain-if, <=6 params, consts above use. Tables are mmap'd through static POINTERS -- a BSS static ARRAY silently crashes the module at startup (banked gotcha). license_tier: ORIGINAL expect_exit: 0 No hw writes (Rule 26).