Answer stability round 1: 0 🔴, 3 🟡 (0 misread); refuse a seeded carry on a portable line, say what undefined means

src/adf/inline-nodes.ts

@@ -38,7 +38,7 @@ export function inlineNodeModel(type: string): InlineNodeModel | undefined {
   return Object.hasOwn(inlineNodes, type) ? inlineNodes[type] : undefined
 }
 
-// Undefined means every mark: the table lists only types the schema restricts. Text is code text, or formatted text, which withholds `border`.
+// Undefined means every mark: a node type outside this module's tables, which the schema restricts nowhere.
 export function takenMarkTypes(node: AdfNode): readonly string[] | undefined {
   if (node.type === 'text') return nodeMarks(node).some((mark) => mark.type === 'code') ? codeTextMarkTypes : formattedTextMarkTypes
   return inlineNodeModel(node.type)?.markTypes

src/markdown/emit/inline-line.ts

@@ -63,9 +63,10 @@ export function openingLinkTakesDirective(nodes: readonly AdfNode[], path: Conve
 }
 
 export function portableLineFallback(nodes: readonly AdfNode[], container: LineContainer, path: ConvertErrorPath): Result<PortableLineFallback | undefined> {
-  const emission = lineSegments(nodes, container, path, withheldMarkFallbacks(nodes, 'portable'))
+  const fallbacks = withheldMarkFallbacks(nodes, 'portable')
+  const emission = lineSegments(nodes, container, path, fallbacks)
   if (!emission.ok) return emission
-  if (emission.value.carries !== undefined) return failure('unsupported-node-shape', 'an inline node on a portable line has no spelling but the carry', path)
+  if (fallbacks.carried.size > 0 || emission.value.carries !== undefined) return failure('unsupported-node-shape', 'an inline node on a portable line has no spelling but the carry', path)
   const verdict = lineVerdict(emission.value.segments, container, 'portable', { kind: 'drop', nodes })
   return success(verdict.kind === 'line' ? undefined : verdict)
 }

src/markdown/portable/adf-to-portable-markdown.test.ts

@@ -416,8 +416,10 @@ test('gives up every highlight run whose own delimiter cannot flank in one fallb
 })
 
 test('refuses a portable line holding a node only the carry spells, at the line', () => {
-  const refused = portableLineFallback([text('x', { attrs: { a: 1 }, type: 'em' })], 'paragraph', ['content', 0])
-  assert.deepEqual(refused.ok ? refused : [refused.error.code, refused.error.path], ['unsupported-node-shape', ['content', 0]])
+  for (const mark of [{ attrs: { a: 1 }, type: 'em' }, { type: 'odd' }]) {
+    const refused = portableLineFallback([text('x', mark)], 'paragraph', ['content', 0])
+    assert.deepEqual(refused.ok ? refused : [refused.error.code, refused.error.path], ['unsupported-node-shape', ['content', 0]])
+  }
 })
 
 test('breaks a line at a newline and trims whitespace at every edge CommonMark strips', () => {