{"abstract":"Touching coverage spans remain separate and create redundant raster work.","category":"Raster clipping","checks":4,"contract":"Return sorted disjoint half-open raster spans after dropping zero/negative lengths and coalescing both overlapping and adjacent spans.","contract_signature":"spans","evaluation_group":"xg-span-merge-touching","failed_approach":"Replacing the merged end with a contained span end shrinks coverage and retains empty spans.","family":"xg-span-merge-touching","id":"FA-10676","implementations":{"attempt":{"sha256":"3c18e45a4b141cf169ba23d2b79cd027860f1d74dc22b74289fc311d5849b593","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(spans):\n    out=[]\n    for left,right in sorted(spans):\n        if out and left<=out[-1][1]: out[-1][1]=right\n        else: out.append([left,right])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*([[0, 2], [2, 4]],)), [[0, 4]])\ncheck('fixture 2', solve(*([[0, 5], [1, 2]],)), [[0, 5]])\ncheck('fixture 3', solve(*([[3, 3], [1, 2]],)), [[1, 2]])\ncheck('fixture 4', solve(*([],)), [])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"001eeec722b5fbb631adb5d8e391219748a25f2196b678036eaa50fafcfa53bf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(spans):\n    out=[]\n    for left,right in sorted(spans):\n        if right<=left: continue\n        if out and left<out[-1][1]: out[-1][1]=max(out[-1][1],right)\n        else: out.append([left,right])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve(*([[0, 2], [2, 4]],)), [[0, 4]])\ncheck('fixture 2', solve(*([[0, 5], [1, 2]],)), [[0, 5]])\ncheck('fixture 3', solve(*([[3, 3], [1, 2]],)), [[1, 2]])\ncheck('fixture 4', solve(*([],)), [])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":" This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xg-span-merge-touching","generated_at":"2026-09-29T14:38:41.200323+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic software graphics stage with explicit channel and coordinate conventions; no hardware, device profile or API behavior is inferred.","root_cause":"Touching coverage spans remain separate and create redundant raster work.","sha256":"a7a9888d5c550ec319262f5c2d0aa8f23384dd63a316e9afbdd223eedd0910e9","title":"Span merge touching · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.327,"exit_code":1,"observations":[{"actual":[[0,4]],"check":"fixture 1","expected":[[0,4]],"passed":true},{"actual":[[0,2]],"check":"fixture 2","expected":[[0,5]],"passed":false},{"actual":[[1,2],[3,3]],"check":"fixture 3","expected":[[1,2]],"passed":false},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0, 4]], \"expected\": [[0, 4]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[0, 2]], \"expected\": [[0, 5]], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [[1, 2], [3, 3]], \"expected\": [[1, 2]], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.409,"exit_code":1,"observations":[{"actual":[[0,2],[2,4]],"check":"fixture 1","expected":[[0,4]],"passed":false},{"actual":[[0,5]],"check":"fixture 2","expected":[[0,5]],"passed":true},{"actual":[[1,2]],"check":"fixture 3","expected":[[1,2]],"passed":true},{"actual":[],"check":"fixture 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0, 2], [2, 4]], \"expected\": [[0, 4]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[0, 5]], \"expected\": [[0, 5]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[1, 2]], \"expected\": [[1, 2]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}