FA-76776 / Email MIME structure / Open access
Choose non-colliding boundaries for nested multiparts: length limit · case 01
Boundaries longer than the 70-character limit are generated.
ROOT CAUSE
The length limit decision evaluates `len(cand) > 76` where the contract requires `len(cand) > 70`.
VERIFIED REPAIR
Use `len(cand) > 70` for the length limit decision and keep every other rule of the model unchanged.
Unsuccessful approach: Rejecting exactly 70 characters refuses a legal boundary. The attempted `len(cand) >= 70` still disagrees with a fixture.
Case contract
Multipart nodes have "parts", leaves have "text". Nodes are visited depth-first (pre-order) and a single counter produces candidates base_1, base_2, ... A candidate is rejected when it occurs in any text anywhere below the node, when it is a prefix of an ancestor boundary or an ancestor boundary is a prefix of it, and a candidate longer than 70 characters makes that node's boundary None (its subtree gets none). Result: boundaries in visiting order.
Why this case matters
A boundary that appears inside a part, or that extends an outer boundary, splits the message at the wrong place.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(tree, base):
out = []
counter = [0]
def contents(n):
if 'parts' in n:
return [x for c in n['parts'] for x in contents(c)]
return [n.get('text', '')]
def assign(n, ancestors):
if 'parts' not in n:
return
texts = contents(n)
while True:
counter[0] += 1
cand = base + '_' + str(counter[0])
if len(cand) > 76:
out.append(None)
return
if any(cand in t for t in texts):
continue
if any(a.startswith(cand) or cand.startswith(a) for a in ancestors):
continue
break
out.append(cand)
for c in n['parts']:
assign(c, ancestors + [cand])
assign(tree, [])
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_CASES = {1: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b1_1 and b1_2'}]}]}, 'b1'), ['b1_3', 'b1_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q1_2 q1_3 q1_4 q1_5 q1_6 q1_7 q1_8 q1_9'}]}]}, 'q1'), ['q1_1', 'q1_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm1'), ['m1_1', 'm1_2', 'm1_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 2: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b2_1 and b2_2'}]}]}, 'b2'), ['b2_3', 'b2_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q2_2 q2_3 q2_4 q2_5 q2_6 q2_7 q2_8 q2_9'}]}]}, 'q2'), ['q2_1', 'q2_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz2'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz2_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm2'), ['m2_1', 'm2_2', 'm2_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 3: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b3_1 and b3_2'}]}]}, 'b3'), ['b3_3', 'b3_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q3_2 q3_3 q3_4 q3_5 q3_6 q3_7 q3_8 q3_9'}]}]}, 'q3'), ['q3_1', 'q3_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz3'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz3_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm3'), ['m3_1', 'm3_2', 'm3_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 4: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b4_1 and b4_2'}]}]}, 'b4'), ['b4_3', 'b4_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q4_2 q4_3 q4_4 q4_5 q4_6 q4_7 q4_8 q4_9'}]}]}, 'q4'), ['q4_1', 'q4_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz4'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz4_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm4'), ['m4_1', 'm4_2', 'm4_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 5: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b5_1 and b5_2'}]}]}, 'b5'), ['b5_3', 'b5_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q5_2 q5_3 q5_4 q5_5 q5_6 q5_7 q5_8 q5_9'}]}]}, 'q5'), ['q5_1', 'q5_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz5'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz5_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm5'), ['m5_1', 'm5_2', 'm5_3']), ('single leaf', ({'text': 'only'}, 'n'), [])]}
for _label, _args, _expected in _CASES[N]:
check(_label, solve(*_args), _expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| collision deep in a later child | ['b1_3', 'b1_4'] | ['b1_3', 'b1_4'] | Passed |
| counter passes ten | ['q1_1', 'q1_20'] | ['q1_1', 'q1_20'] | Passed |
| exactly seventy characters | ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1'] | ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1'] | Passed |
| seventy-one characters | ['yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy_1'] | [None] | Failed |
| plain nesting | ['m1_1', 'm1_2', 'm1_3'] | ['m1_1', 'm1_2', 'm1_3'] | Passed |
| single leaf | [] | [] | Passed |
SHA-256 / 481734ad8618db88f621f02e1b7a30759396abcc2af656956b0d9cd53daef236
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(tree, base):
out = []
counter = [0]
def contents(n):
if 'parts' in n:
return [x for c in n['parts'] for x in contents(c)]
return [n.get('text', '')]
def assign(n, ancestors):
if 'parts' not in n:
return
texts = contents(n)
while True:
counter[0] += 1
cand = base + '_' + str(counter[0])
if len(cand) >= 70:
out.append(None)
return
if any(cand in t for t in texts):
continue
if any(a.startswith(cand) or cand.startswith(a) for a in ancestors):
continue
break
out.append(cand)
for c in n['parts']:
assign(c, ancestors + [cand])
assign(tree, [])
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_CASES = {1: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b1_1 and b1_2'}]}]}, 'b1'), ['b1_3', 'b1_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q1_2 q1_3 q1_4 q1_5 q1_6 q1_7 q1_8 q1_9'}]}]}, 'q1'), ['q1_1', 'q1_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm1'), ['m1_1', 'm1_2', 'm1_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 2: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b2_1 and b2_2'}]}]}, 'b2'), ['b2_3', 'b2_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q2_2 q2_3 q2_4 q2_5 q2_6 q2_7 q2_8 q2_9'}]}]}, 'q2'), ['q2_1', 'q2_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz2'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz2_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm2'), ['m2_1', 'm2_2', 'm2_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 3: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b3_1 and b3_2'}]}]}, 'b3'), ['b3_3', 'b3_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q3_2 q3_3 q3_4 q3_5 q3_6 q3_7 q3_8 q3_9'}]}]}, 'q3'), ['q3_1', 'q3_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz3'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz3_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm3'), ['m3_1', 'm3_2', 'm3_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 4: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b4_1 and b4_2'}]}]}, 'b4'), ['b4_3', 'b4_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q4_2 q4_3 q4_4 q4_5 q4_6 q4_7 q4_8 q4_9'}]}]}, 'q4'), ['q4_1', 'q4_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz4'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz4_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm4'), ['m4_1', 'm4_2', 'm4_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 5: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b5_1 and b5_2'}]}]}, 'b5'), ['b5_3', 'b5_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q5_2 q5_3 q5_4 q5_5 q5_6 q5_7 q5_8 q5_9'}]}]}, 'q5'), ['q5_1', 'q5_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz5'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz5_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm5'), ['m5_1', 'm5_2', 'm5_3']), ('single leaf', ({'text': 'only'}, 'n'), [])]}
for _label, _args, _expected in _CASES[N]:
check(_label, solve(*_args), _expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| collision deep in a later child | ['b1_3', 'b1_4'] | ['b1_3', 'b1_4'] | Passed |
| counter passes ten | ['q1_1', 'q1_20'] | ['q1_1', 'q1_20'] | Passed |
| exactly seventy characters | [None] | ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1'] | Failed |
| seventy-one characters | [None] | [None] | Passed |
| plain nesting | ['m1_1', 'm1_2', 'm1_3'] | ['m1_1', 'm1_2', 'm1_3'] | Passed |
| single leaf | [] | [] | Passed |
SHA-256 / e115d2f4a96ac652ca4f91018d8f57adb38194b6fd8434552a7f5097c06f0201
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(tree, base):
out = []
counter = [0]
def contents(n):
if 'parts' in n:
return [x for c in n['parts'] for x in contents(c)]
return [n.get('text', '')]
def assign(n, ancestors):
if 'parts' not in n:
return
texts = contents(n)
while True:
counter[0] += 1
cand = base + '_' + str(counter[0])
if len(cand) > 70:
out.append(None)
return
if any(cand in t for t in texts):
continue
if any(a.startswith(cand) or cand.startswith(a) for a in ancestors):
continue
break
out.append(cand)
for c in n['parts']:
assign(c, ancestors + [cand])
assign(tree, [])
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_CASES = {1: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b1_1 and b1_2'}]}]}, 'b1'), ['b1_3', 'b1_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q1_2 q1_3 q1_4 q1_5 q1_6 q1_7 q1_8 q1_9'}]}]}, 'q1'), ['q1_1', 'q1_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm1'), ['m1_1', 'm1_2', 'm1_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 2: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b2_1 and b2_2'}]}]}, 'b2'), ['b2_3', 'b2_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q2_2 q2_3 q2_4 q2_5 q2_6 q2_7 q2_8 q2_9'}]}]}, 'q2'), ['q2_1', 'q2_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz2'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz2_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm2'), ['m2_1', 'm2_2', 'm2_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 3: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b3_1 and b3_2'}]}]}, 'b3'), ['b3_3', 'b3_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q3_2 q3_3 q3_4 q3_5 q3_6 q3_7 q3_8 q3_9'}]}]}, 'q3'), ['q3_1', 'q3_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz3'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz3_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm3'), ['m3_1', 'm3_2', 'm3_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 4: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b4_1 and b4_2'}]}]}, 'b4'), ['b4_3', 'b4_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q4_2 q4_3 q4_4 q4_5 q4_6 q4_7 q4_8 q4_9'}]}]}, 'q4'), ['q4_1', 'q4_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz4'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz4_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm4'), ['m4_1', 'm4_2', 'm4_3']), ('single leaf', ({'text': 'only'}, 'n'), [])], 5: [('collision deep in a later child', ({'parts': [{'text': 'x'}, {'parts': [{'text': 'has b5_1 and b5_2'}]}]}, 'b5'), ['b5_3', 'b5_4']), ('counter passes ten', ({'parts': [{'parts': [{'text': 'q5_2 q5_3 q5_4 q5_5 q5_6 q5_7 q5_8 q5_9'}]}]}, 'q5'), ['q5_1', 'q5_20']), ('exactly seventy characters', ({'parts': [{'text': 'x'}]}, 'zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz5'), ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz5_1']), ('seventy-one characters', ({'parts': [{'text': 'x'}]}, 'yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy'), [None]), ('plain nesting', ({'parts': [{'parts': [{'text': 'a'}]}, {'parts': [{'text': 'b'}]}]}, 'm5'), ['m5_1', 'm5_2', 'm5_3']), ('single leaf', ({'text': 'only'}, 'n'), [])]}
for _label, _args, _expected in _CASES[N]:
check(_label, solve(*_args), _expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| collision deep in a later child | ['b1_3', 'b1_4'] | ['b1_3', 'b1_4'] | Passed |
| counter passes ten | ['q1_1', 'q1_20'] | ['q1_1', 'q1_20'] | Passed |
| exactly seventy characters | ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1'] | ['zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz1_1'] | Passed |
| seventy-one characters | [None] | [None] | Passed |
| plain nesting | ['m1_1', 'm1_2', 'm1_3'] | ['m1_1', 'm1_2', 'm1_3'] | Passed |
| single leaf | [] | [] | Passed |
SHA-256 / 8fec48d91959ec9b11219a94e67786c16320a494d7b77798a34c5c055849d1be
Verification & scope
Stipulated offline model over pre-parsed MIME dictionaries; not a conforming MIME parser, generator or mail client. 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.
Observations recorded using Python 3.12.14 at 2026-09-29T14:49:19.350593+00:00.
Case digest / 1eb4f328fc54ed2712ddbe70da61d1974de30e4f8cbbef3b574ce7f1de49a59e