Fix regression with escaped brackets

Author: blakeembrey

index.js

@@ -91,14 +91,26 @@ function pathtoRegexp(path, keys, options) {
       var len = keys.length
 
       while (len-- > keysOffset && keys[len].offset > index) {
-        keys[len].offset += 3;
+        keys[len].offset += 3; // Replacement length minus asterisk length.
       }
 
       return '(.*)';
     });
 
   // This is a workaround for handling unnamed matching groups.
   while (m = MATCHING_GROUP_REGEXP.exec(path)) {
+    var escapeCount = 0;
+    var index = m.index;
+
+    while (path.charAt(--index) === '\\') {
+      escapeCount++;
+    }
+
+    // It's possible to escape the bracket.
+    if (escapeCount % 2 === 1) {
+      continue;
+    }
+
     if (keysOffset + i === keys.length || keys[keysOffset + i].offset > m.index) {
       keys.splice(keysOffset + i, 0, {
         name: name++, // Unnamed matching groups must be consistently linear.

test.js

@@ -764,4 +764,44 @@ describe('path-to-regexp', function () {
       assert.equal(m[3], 'path');
     });
   });
+
+  describe('regressions', function () {
+    it('should work with strongloop/expressjs.com#417', function () {
+      var params = [];
+      var re = pathToRegExp('/:foo\\(:bar?\\)', params);
+      var m;
+
+      assert.equal(params.length, 2);
+      assert.equal(params[0].name, 'foo');
+      assert.equal(params[0].optional, false);
+      assert.equal(params[1].name, 'bar');
+      assert.equal(params[1].optional, true);
+
+      m = re.exec('/hello(world)');
+
+      assert.equal(m.length, 3);
+      assert.equal(m[0], '/hello(world)');
+      assert.equal(m[1], 'hello');
+      assert.equal(m[2], 'world');
+    });
+
+    it('should handle an escaped escape character', function () {
+      var params = [];
+      var re = pathToRegExp('/:foo\\\\(world)', params);
+      var m;
+
+      assert.equal(params.length, 2);
+      assert.equal(params[0].name, 'foo');
+      assert.equal(params[0].optional, false);
+      assert.equal(params[1].name, 0);
+      assert.equal(params[1].optional, false);
+
+      m = re.exec('/hello\\world');
+
+      assert.equal(m.length, 3);
+      assert.equal(m[0], '/hello\\world');
+      assert.equal(m[1], 'hello');
+      assert.equal(m[2], 'world');
+    });
+  });
 });