Answer the stability pass: pin the deeper stack, the quoted newline and the closing fence

src/markdown/parse/blocks.test.ts

@@ -102,6 +102,7 @@ test('holds a directive container open until the fence that closes it', () => {
 test('names the directive fence a container does not sit longer than', () => {
   assert.deepEqual(faults(':::panel info\n:::expand\nPart.\n:::\n'), ["a directive fence line is at least as long as the container's 3 colons"])
   assert.deepEqual(faults('::::panel info\n:::\n::::\n'), ['a closing fence is shorter than the 4 colons it would close'])
+  assert.deepEqual(faults('::::panel info\n:::expand\nPart.\n:::::\n::::\n'), [])
   assert.deepEqual(faults(':::panel info\nPart.\n'), ['a container fenced with 3 colons is unclosed'])
   assert.deepEqual(faults('- :::panel info\n\nPart.\n'), ['a container fenced with 3 colons is unclosed'])
   assert.deepEqual(faults('Part.\n\n:::\n'), ['a closing fence closes no open container'])

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

@@ -130,7 +130,6 @@ test('claims a block-level colon run with no directive to parse it', () => {
   assert.equal(code(markdownToAdf(':::\n')), 'malformed-directive')
   assert.equal(code(markdownToAdf('::Panel\n')), 'malformed-directive')
   assert.equal(code(markdownToAdf('::panel {a=1 a=2}\n')), 'malformed-directive')
-  assert.deepEqual(path(markdownToAdf('Part.\n:::x\n')), ['content', 1])
   assert.deepEqual(content(markdownToAdf(':10:30\n')), [paragraph(':10:30')])
   assert.deepEqual(content(markdownToAdf(':: two\n')), [paragraph(':: two')])
 })
@@ -141,6 +140,8 @@ test('reads the three directive forms, and names the node none of them reads bac
   assert.equal(code(markdownToAdf('Part :mention[@A]{id=b1c2}.\n')), 'unknown-directive-name')
   assert.equal(content(markdownToAdf('::rule\n')), 'unknown-directive-name: the directive name rule reads back to no node')
   assert.deepEqual(path(markdownToAdf('Part.\n\n::rule\n')), ['content', 1])
+  assert.equal(content(markdownToAdf('Part.\n:::x\n')), 'malformed-directive: a container fenced with 3 colons is unclosed')
+  assert.deepEqual(path(markdownToAdf('Part.\n:::x\n')), ['content', 1])
 })
 
 test('leaves the colon that opens no directive the text it is', () => {