Fix the false claims round one found, and refuse the content a code span dropped

AGENTS.md

@@ -82,8 +82,8 @@ closed list a consumer may switch exhaustively, the message free text, the path
 from the document root. Adding, removing or renaming a code is breaking, so a milestone meeting a
 new failure cause reuses a code where one fits; the list is complete at `0.1.0`. A code names the
 cause; where one cause recurs across node types, one code covers them all and `path` and `message`
-say which. A cause the carry answers gets no code: no mark refuses, since a mark no spelling writes
-rides the carry with its node.
+say which. A cause the carry answers gets no code: a mark no spelling writes rides the carry with
+its node.
 
 ## 9. Release automation
 
@@ -154,9 +154,8 @@ One-line commit messages and PR titles; short PR summaries. No AI-attribution ma
 No wiki markup (§1), no network or filesystem I/O, no name→id resolution (§3), no ADF schema
 validation or exported validator — a refusal that keeps the round-trip is not schema validation,
 so the one a spelled node carrying the same mark type twice earns stays, no shipped CSS (§4), no
-streaming APIs, no performance budget —
-conversions are O(n), real documents are kilobytes. A CLI is a later goal (`todo.md`), not a
-non-goal.
+streaming APIs, no performance budget — real documents are kilobytes. A CLI is a later goal
+(`todo.md`), not a non-goal.
 
 ## 15. The working loop
 

corpus/round-trip/combinations/carry-marks.json

@@ -87,6 +87,41 @@
         }
       ],
       "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "text": "a",
+          "type": "text"
+        },
+        {
+          "marks": [
+            {
+              "type": "em"
+            }
+          ],
+          "text": ".",
+          "type": "text"
+        },
+        {
+          "text": "b",
+          "type": "text"
+        },
+        {
+          "marks": [
+            {
+              "type": "strong"
+            }
+          ],
+          "text": ",",
+          "type": "text"
+        },
+        {
+          "text": "c",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
     }
   ],
   "type": "doc",

corpus/round-trip/combinations/carry-marks.md

@@ -7,3 +7,5 @@ Reviewed :adf{json="{\"marks\":[{\"attrs\":{\"annotationType\":\"inlineComment\"
 :adf{json="{\"marks\":[{\"type\":\"code\"}],\"text\":\"a\\nb\",\"type\":\"text\"}"}
 
 :adf{json="{\"marks\":[{\"type\":\"link\"}],\"text\":\"Release notes\",\"type\":\"text\"}"}
+
+a:adf{json="{\"marks\":[{\"type\":\"em\"}],\"text\":\".\",\"type\":\"text\"}"}b:adf{json="{\"marks\":[{\"type\":\"strong\"}],\"text\":\",\",\"type\":\"text\"}"}c

spec/flavour.md

@@ -386,12 +386,14 @@ restores the array, not a set — and opens each spelling once over the longest
 inline nodes carrying an identical mark, attributes included, at that depth. A run breaks at every
 node the emitter carries, so no emitted carry sits inside a mark spelling.
 
-An inline node whose marks no nesting spells — a mark type not listed here, an attribute no
-spelling holds or one a spelling needs and the mark lacks, an order putting a code span outside
-another mark, `code` over anything but a text node or over text holding a newline, or a spelling
-CommonMark's flanking rules cannot open or close where the run sits (`un**-real**istic`) — rides
-the inline carry whole. An opaque carry inside a mark spelling is a
-named error in input: the carry restores its node exactly, marks included (AGENTS.md §3).
+An inline node whose marks no nesting spells — a mark type not listed here, an attrs key its
+spelling does not list, a value that is not the spelling's type, an attribute the spelling needs
+and the mark lacks, an order putting a code span outside another mark, `code` over anything but a
+text node or over text holding a newline, or a spelling CommonMark's flanking rules cannot open or
+close where the run sits (`un**-real**istic`) — rides the inline carry whole. A value the spelling
+holds but CommonMark cannot write — a link destination or title — is a named error instead. An
+opaque carry inside a mark spelling is a named error in input: the carry restores its node
+exactly, marks included (AGENTS.md §3).
 
 ```
 :textColor[**Overdue**]{color="#ae2e24"}, H:subsup[2]{type=sub}O, :underline[signed].

src/adf-to-markdown.test.ts

@@ -317,9 +317,12 @@ test('refuses the characters CommonMark rewrites', () => {
   assert.equal(code(adfToMarkdown(document({ content: [{ text: '', type: 'text' }], type: 'codeBlock' }))), 'unsupported-node-shape')
 })
 
-test('refuses a text node carrying no text at all', () => {
+test('refuses a text node the spelling would empty out', () => {
+  const nested: AdfNode[] = [{ text: 'lost', type: 'text' }]
   assert.equal(code(adfToMarkdown(document(paragraph({ text: '', type: 'text' })))), 'unsupported-node-shape')
   assert.equal(code(adfToMarkdown(document(paragraph({ marks: [{ type: 'code' }], text: '', type: 'text' })))), 'unsupported-node-shape')
+  assert.equal(code(adfToMarkdown(document(paragraph({ content: nested, text: 'x', type: 'text' })))), 'unsupported-node-shape')
+  assert.equal(code(adfToMarkdown(document(paragraph({ content: nested, marks: [{ type: 'code' }], text: 'x', type: 'text' })))), 'unsupported-node-shape')
 })
 
 test('carries a mark run whose edge holds whitespace CommonMark flanking counts', () => {

src/adf-to-markdown.ts

@@ -110,13 +110,11 @@ function commonMarkContainer(body: Result<EmittedBody>): Result<EmittedBlock> {
 
 function emitDirectiveBlock(node: AdfNode, directive: BlockDirective, path: ConvertErrorPath, depth: number): Result<EmittedBlock> {
   if (node.text !== undefined) return failure('unsupported-node-shape', `a ${node.type} carries no text`, path)
+  const content = node.content ?? []
+  if (directive.body === 'none' && content.length > 0) return failure('unsupported-node-shape', `a ${node.type} holds no content`, path)
   const header = spellDirectiveHeader(node, directive)
   if (header === undefined) return commonMarkLine(carriedBlock(node, path))
-  const content = node.content ?? []
-  if (directive.body === 'none') {
-    if (content.length > 0) return failure('unsupported-node-shape', `a ${node.type} holds no content`, path)
-    return success({ fenceColons: 2, spelling: 'directive', text: `::${header}` })
-  }
+  if (directive.body === 'none') return success({ fenceColons: 2, spelling: 'directive', text: `::${header}` })
   const body = directive.body === 'inline' ? emitInlineBody(content, path) : emitBlocks(content, 'directive', path, depth + 1)
   if (!body.ok) return body
   const fenceColons = Math.max(3, body.value.fenceColons + 1)

src/markdown-inline.ts

@@ -48,7 +48,7 @@ export function tryImageLine(alt: string | undefined, href: string, path: Conver
   return attempt.ok ? attempt.value.line : undefined
 }
 
-// A demand names a run no spelling holds, and a carried node joins no run, so every pass carries one more node.
+// A demand names a run no spelling holds, and a carried node joins no run, so every pass carries at least one more node.
 function emitLine(nodes: readonly AdfNode[], container: LineContainer, path: ConvertErrorPath): Result<EmittedLine> {
   const carried = new Set<number>()
   for (;;) {
@@ -262,6 +262,7 @@ function emitCodeSpan(nodes: readonly AdfNode[], depth: number, range: NodeRange
   for (const node of nodes) {
     if (node.type !== 'text' || (node.marks ?? []).length !== depth + 1) return success({ carry: range })
     if (typeof node.text !== 'string' || node.text === '') return failure('unsupported-node-shape', 'a text node holds text', path)
+    if ((node.content ?? []).length > 0) return failure('unsupported-node-shape', 'a text node holds no content', path)
     text += node.text
   }
   if (/[\n\r]/.test(text)) return success({ carry: range })

todo.md

@@ -109,7 +109,7 @@ detail is settled at its own milestone.
           which leaves the refusals a container's own spelling owns. The flanking trigger 2e2
           added to that list is the odd one out: `unspellableMark` finds it after assembly and
           names a mark type against the line's path, so the failing run needs identifying before
-          the carry can replace the refusal `corpus/unspellable/mark-inside-word` pins.
+          the carry can replace the refusal `mark-inside-word` pinned.
     - [ ] **2e5 — Combined documents and the collision property.** Documents combining nodes rather
           than isolating one, and the gate's collision property: no two corpus documents may emit
           the same bytes — one spelling for two documents is a round-trip break no parser can undo,