Update MD013/line-length not to report long link-only lines (fixes #36).

lib/rules.js

@@ -56,7 +56,7 @@ function unorderedListStyleFor(token) {
       return "dash";
     case "+":
       return "plus";
-    case "*":
+    // case "*":
     default:
       return "asterisk";
   }
@@ -435,14 +435,25 @@ module.exports = [
           headerLineNumbers.push(heading.lineNumber);
         });
       }
-      var re = longLineReFunc(params.options);
+      var linkOnlyLineNumbers = [];
+      filterTokens(params, "inline", function forToken(token) {
+        if (((token.children.length === 2) || (token.children.length === 3)) &&
+            (token.children[0].type === "link_open") &&
+            (token.children[token.children.length - 1].type === "link_close")) {
+          linkOnlyLineNumbers.push(token.lineNumber);
+        }
+      });
+      var longLineRe = longLineReFunc(params.options);
+      var labelRe = /^\s*\[.*[^\\]]:/;
       forEachLine(params,
         function forLine(line, lineIndex, inCode, onFence, inTable) {
           var lineNumber = lineIndex + 1;
           if ((includeCodeBlocks || !inCode) &&
               (includeTables || !inTable) &&
               (includeHeaders || (headerLineNumbers.indexOf(lineNumber)) < 0) &&
-              re.test(line)) {
+              (linkOnlyLineNumbers.indexOf(lineNumber) < 0) &&
+              longLineRe.test(line) &&
+              !labelRe.test(line)) {
             errors.addDetailIf(lineNumber, lineLength, line.length);
           }
         });

test/long_lines.md

@@ -1,3 +1,23 @@
 This is a very very very very very very very very very very very very very very long line {MD013}
 
 This line however, while very long, doesn't have whitespace after the 80th columnwhichallowsforURLsandotherlongthings.
+
+[This long line is comprised entirely of a link](http://example.com "This is the long link's title")
+
+> [This long line is comprised entirely of a link](http://example.com "This is the long link's title")
+
+    [This long line is comprised entirely of a link](http://example.com "But is inside a code block") {MD013}
+
+This [long line is comprised mostly of a link](http://example.com "This is the long link's title") {MD013}
+
+[This long line is comprised mostly of a link](http://example.com "This is the long link's title") text {MD013}
+
+This long line includes a simple [reference][label] link and is long enough to violate the rule. {MD013}
+
+[This long line is comprised entirely of a reference link and is long enough to violate the rule][label]
+
+[label]: http://example.org "Title for a link reference that is itself long enough to violate the rule"
+
+[Link to broken label][notlabel]
+
+[notlabel\]: notlink "Invalid syntax for a link label because the right bracket is backslash-escaped {MD013}"