fix for sirthias#222

Author: vsch

CHANGELOG

@@ -75,6 +75,8 @@ This function is also called for VerbatimNode from the DefaultVerbatimSerializer
     preceded by alphanumeric for _ and as long as not surrounded by spaces for * instead
     of only when preceded by spaces.
 
+- Added allowing code fenced blocks with all blank lines
+
 Version 1.6.0 (2015-09-18)
 --------------------------
 - Fixed collision between ANCHORLINKS and STRIKETHROUGH, WIKILINKS extensions (#161)

src/main/java/org/pegdown/DefaultVerbatimSerializer.java

@@ -17,7 +17,7 @@ public void serialize(final VerbatimNode node, final Printer printer) {
         printer.println().print("<pre><code").print(printer.preview(node, "code", attributes, false)).print('>');
         String text = node.getText();
         // print HTML breaks for all initial newlines
-        while (text.charAt(0) == '\n') {
+        while (!text.isEmpty() && text.charAt(0) == '\n') {
             printer.print("<br/>");
             text = text.substring(1);
         }

src/main/java/org/pegdown/Parser.java

@@ -222,12 +222,14 @@ public Rule FencedCodeBlock() {
         Var<Integer> markerLength = new Var<Integer>();
         return NodeSequence(
                 // vsch: test to see if what appears to be a code fence is just inline code
+                // vsch: change to accept code fence with all blank lines
                 CodeFence(markerLength),
-                TestNot(CodeFence(markerLength)), // prevent empty matches
-                ZeroOrMore(BlankLine(), text.append('\n')),
-                OneOrMore(TestNot(Newline(), CodeFence(markerLength)), ANY, text.append(matchedChar())),
-                Newline(),
-                push(new VerbatimNode(text.appended('\n').getString(), popAsString())),
+                OneOrMore(
+                        TestNot(CodeFence(markerLength)),
+                        ZeroOrMore(TestNot(Newline()), ANY, text.append(matchedChar())),
+                        Sequence(Newline(), text.append(matchedChar()))
+                ),
+                push(new VerbatimNode(text.getString(), popAsString())),
                 CodeFence(markerLength), drop()
         );
     }
@@ -1461,8 +1463,7 @@ ticks, Sp(),
                         FirstOf(
                                 Sequence(TestNot('`'), Nonspacechar()),
                                 Sequence(TestNot(ticks), OneOrMore('`')),
-                                Sequence(TestNot(Sp(), ticks),
-                                        FirstOf(Spacechar(), Sequence(Newline(), TestNot(BlankLine()))))
+                                Sequence(TestNot(Sp(), ticks), FirstOf(Spacechar(), Sequence(Newline(), TestNot(BlankLine()))))
                         )
                 ),
                 push(new CodeNode(match())),