4.2: an autolink holding a backtick gives way inside a directive's content

corpus/round-trip/combinations/directive-autolink-backtick.json

@@ -0,0 +1,50 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "marks": [
+            {
+              "type": "underline"
+            },
+            {
+              "attrs": {
+                "href": "http://a`b"
+              },
+              "type": "link"
+            }
+          ],
+          "text": "http://a`b",
+          "type": "text"
+        },
+        {
+          "text": "`c",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "marks": [
+            {
+              "type": "underline"
+            },
+            {
+              "attrs": {
+                "href": "http://d`e"
+              },
+              "type": "link"
+            }
+          ],
+          "text": "http://d`e",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/combinations/directive-autolink-backtick.md

@@ -0,0 +1,3 @@
+:underline[[http://a\`b](http://a\`b)]`c
+
+:underline[[http://d\`e](http://d`e)]

spec/flavour.md

@@ -48,7 +48,8 @@ normalizes to it through the round-trip.
   title; title in double quotes. A backslash escapes a parenthesis the destination leaves
   unbalanced, and a quote inside the title; a balanced pair stays bare. `<url>` autolink form only
   when the text equals the destination and the destination is a valid CommonMark autolink
-  (absolute URI).
+  (absolute URI) — inside an inline directive's `[content]`, one holding no backtick and no
+  unbalanced bracket.
 - Paragraphs on one line — no soft wrapping; a soft line break in input becomes a single space.
 - Entity references in input decode to their characters; output backslash-escapes only where text
   would otherwise parse as syntax, scanning the assembled line rather than each text node: escape
@@ -131,10 +132,10 @@ each a named error naming the spelling to write instead.
 
 **Escaping**: the emitter backslash-escapes whatever literal text would otherwise parse as
 directive syntax — the leading `:` of a would-be directive, `]` inside content, a bracket a link's
-destination and title inside content leave unbalanced (an autolink holding one takes the
-`[text](url)` form) and a backtick there that would open a code span, a `{` right after a
-directive's closing `]`, which would otherwise be read as the attributes it has none of; outside
-code spans and code blocks, a backslash before `:` in input yields a literal colon.
+destination and title inside content leave unbalanced and a backtick there that would open a code
+span, a `{` right after a directive's closing `]`, which would otherwise be read as the attributes
+it has none of; outside code spans and code blocks, a backslash before `:` in input yields a
+literal colon.
 
 **Malformed directives are error results**, named: an unclosed container at end of input, a body
 fence line of the container's length or longer, a bare colon-run line outside any container or

src/markdown/emit/inline-line.ts

@@ -284,8 +284,8 @@ function emitLink(nodes: readonly AdfNode[], mark: AdfMark, depth: number, range
   if (typeof href !== 'string') return success({ carry: range })
   const node = nodes[0]
   const bare = nodes.length === 1 && node !== undefined && node.type === 'text' && node.text === href && nodeMarks(node).length === depth + 1
-  const balanced = !context.bracketed || escapeUnbalanced(href, '[', ']') === href
-  if (bare && balanced && title === undefined && isAutolink(href) && !holdsEntityReference(href)) return success({ segments: [syntax(`<${href}>`)] })
+  const autolinkHolds = !context.bracketed || (!href.includes('`') && escapeUnbalanced(href, '[', ']') === href)
+  if (bare && autolinkHolds && title === undefined && isAutolink(href) && !holdsEntityReference(href)) return success({ segments: [syntax(`<${href}>`)] })
   const target = spellLinkTarget(href, typeof title === 'string' ? title : undefined, path)
   if (!target.ok) return target
   const inner = emitRun(nodes, depth + 1, range.first, { ...context, bracketed: true })