FA-76356 / Email MIME structure / Open access

Assign IMAP-style section numbers to body parts: one based children · case 01

Every part is fetched with a section number one lower than the server uses.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The one based children decision evaluates `enumerate(node['parts'])` where the contract requires `enumerate(node['parts'], 1)`.

THE FAILURE

The one based children decision evaluates `enumerate(node['parts'])` where the contract requires `enumerate(node['parts'], 1)`.

Unsuccessful approach: Starting at one only for top-level children still misnumbers nested parts. The attempted `enumerate(node['parts'], 1 if not prefix else 0)` still disagrees with a fixture.

Case contract

Returns [section, type] for every non-multipart entity in depth-first order. A single-part message body is section "1". Children of a multipart are numbered 1..n under the parent's number (nested multiparts get their own number). A message/rfc822 part is listed itself; if its encapsulated body is multipart, that body's children are numbered directly under the message part (P.1, P.2...); a single-part encapsulated body is P.1.

Why this case matters

Section numbers are how clients fetch individual parts; off-by-one numbering downloads the wrong attachment.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tree):
    out = []
    def walk(node, prefix):
        t = node['type']
        if t.startswith('multipart/'):
            for i, child in enumerate(node['parts']):
                walk(child, prefix + [str(i)])
        elif t == 'message/rfc822':
            out.append(['.'.join(prefix), t])
            inner = node['body']
            if inner['type'].startswith('multipart/'):
                walk(inner, prefix)
            else:
                walk(inner, prefix + ['1'])
        else:
            out.append(['.'.join(prefix) or '1', t])
    walk(tree, [])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_CASES = {1: [('single part message', ({'type': 'text/plain'},), [['1', 'text/plain']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 2: [('single part message', ({'type': 'text/html'},), [['1', 'text/html']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 3: [('single part message', ({'type': 'application/pdf'},), [['1', 'application/pdf']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream'], ['4', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 4: [('single part message', ({'type': 'image/png'},), [['1', 'image/png']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream'], ['4', 'application/octet-stream'], ['5', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 5: [('single part message', ({'type': 'text/calendar'},), [['1', 'text/calendar']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream'], ['4', 'application/octet-stream'], ['5', 'application/octet-stream'], ['6', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])]}
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
single part message	`[['1', 'text/plain']]`	`[['1', 'text/plain']]`	Passed
flat mixed	`[['0', 'text/plain'], ['1', 'application/octet-stream']]`	`[['1', 'text/plain'], ['2', 'application/octet-stream']]`	Failed
alternative inside mixed	`[['0.0', 'text/plain'], ['0.1', 'text/html'], ['1', 'application/pdf']]`	`[['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]`	Failed
attached multipart message	`[['0', 'text/plain'], ['1', 'message/rfc822'], ['1.0', 'text/plain'], ['1.1', 'image/jpeg']]`	`[['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]`	Failed
attached single part message	`[['0', 'message/rfc822'], ['0.1', 'text/plain']]`	`[['1', 'message/rfc822'], ['1.1', 'text/plain']]`	Failed
related and forwarded alternative	`[['0.0', 'text/html'], ['0.1', 'image/gif'], ['1', 'message/rfc822'], ['1.0', 'text/plain'], ['1.1', 'text/html']]`	`[['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']]`	Failed

SHA-256 / 9fc593f73521e4fa40065aee95f7362361cd878c7e0e269d36689857f392d3d3

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tree):
    out = []
    def walk(node, prefix):
        t = node['type']
        if t.startswith('multipart/'):
            for i, child in enumerate(node['parts'], 1 if not prefix else 0):
                walk(child, prefix + [str(i)])
        elif t == 'message/rfc822':
            out.append(['.'.join(prefix), t])
            inner = node['body']
            if inner['type'].startswith('multipart/'):
                walk(inner, prefix)
            else:
                walk(inner, prefix + ['1'])
        else:
            out.append(['.'.join(prefix) or '1', t])
    walk(tree, [])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_CASES = {1: [('single part message', ({'type': 'text/plain'},), [['1', 'text/plain']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 2: [('single part message', ({'type': 'text/html'},), [['1', 'text/html']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 3: [('single part message', ({'type': 'application/pdf'},), [['1', 'application/pdf']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream'], ['4', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 4: [('single part message', ({'type': 'image/png'},), [['1', 'image/png']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream'], ['4', 'application/octet-stream'], ['5', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])], 5: [('single part message', ({'type': 'text/calendar'},), [['1', 'text/calendar']]), ('flat mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}, {'type': 'application/octet-stream'}]},), [['1', 'text/plain'], ['2', 'application/octet-stream'], ['3', 'application/octet-stream'], ['4', 'application/octet-stream'], ['5', 'application/octet-stream'], ['6', 'application/octet-stream']]), ('alternative inside mixed', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}, {'type': 'application/pdf'}]},), [['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]), ('attached multipart message', ({'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'message/rfc822', 'body': {'type': 'multipart/mixed', 'parts': [{'type': 'text/plain'}, {'type': 'image/jpeg'}]}}]},), [['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]), ('attached single part message', ({'type': 'multipart/mixed', 'parts': [{'type': 'message/rfc822', 'body': {'type': 'text/plain'}}]},), [['1', 'message/rfc822'], ['1.1', 'text/plain']]), ('related and forwarded alternative', ({'type': 'multipart/mixed', 'parts': [{'type': 'multipart/related', 'parts': [{'type': 'text/html'}, {'type': 'image/gif'}]}, {'type': 'message/rfc822', 'body': {'type': 'multipart/alternative', 'parts': [{'type': 'text/plain'}, {'type': 'text/html'}]}}]},), [['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']])]}
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
single part message	`[['1', 'text/plain']]`	`[['1', 'text/plain']]`	Passed
flat mixed	`[['1', 'text/plain'], ['2', 'application/octet-stream']]`	`[['1', 'text/plain'], ['2', 'application/octet-stream']]`	Passed
alternative inside mixed	`[['1.0', 'text/plain'], ['1.1', 'text/html'], ['2', 'application/pdf']]`	`[['1.1', 'text/plain'], ['1.2', 'text/html'], ['2', 'application/pdf']]`	Failed
attached multipart message	`[['1', 'text/plain'], ['2', 'message/rfc822'], ['2.0', 'text/plain'], ['2.1', 'image/jpeg']]`	`[['1', 'text/plain'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'image/jpeg']]`	Failed
attached single part message	`[['1', 'message/rfc822'], ['1.1', 'text/plain']]`	`[['1', 'message/rfc822'], ['1.1', 'text/plain']]`	Passed
related and forwarded alternative	`[['1.0', 'text/html'], ['1.1', 'image/gif'], ['2', 'message/rfc822'], ['2.0', 'text/plain'], ['2.1', 'text/html']]`	`[['1.1', 'text/html'], ['1.2', 'image/gif'], ['2', 'message/rfc822'], ['2.1', 'text/plain'], ['2.2', 'text/html']]`	Failed

SHA-256 / 7d3ad163a934f5877d1dfe18786840f8838f236921cb3b6ab261d3c88973365c

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

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 2026-09-29T14:49:15.829963+00:00.

Case digest / 4046db5fe1266a45ee772cc9dcc8d513b41d7ca63b68b889a326bf8d3b94ba19