[String] Fixed a crash when parsing an empty documentation comment.

CHANGELOG.md

@@ -1,3 +1,20 @@
+## Master
+
+##### Breaking
+
+None.
+
+##### Enhancements
+
+None.
+
+##### Bug Fixes
+
+* Fixed a crash when parsing an empty documentation comment.  
+  [JP Simard](https://github.com/jpsim)
+  [#236](https://github.com/realm/jazzy/issues/236)
+
+
 ## 0.4.3
 
 ##### Breaking

Source/SourceKittenFramework/String+SourceKitten.swift

@@ -53,6 +53,9 @@ extension NSString {
     :param: characterSet Character set to check for membership.
     */
     public func stringByTrimmingTrailingCharactersInSet(characterSet: NSCharacterSet) -> String {
+        if length == 0 {
+            return self as String
+        }
         var charBuffer = [unichar](count: length, repeatedValue: 0)
         getCharacters(&charBuffer)
         for newLength in reverse(1...length) {

Source/SourceKittenFrameworkTests/StringTests.swift

@@ -25,6 +25,7 @@ class StringTests: XCTestCase {
     }
 
     func testStringByTrimmingTrailingCharactersInSet() {
+        XCTAssertEqual("".stringByTrimmingTrailingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()), "")
         XCTAssertEqual(" a ".stringByTrimmingTrailingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()), " a")
     }