Preserve empty lines in code blocks

Partial fix for #183. Some lines are still being lost. When the processors are run, one line is lost. When their calling code is comments out (completely skiped) a line is still lost if more than 3 exist in a row.

Also need to add some tests for this.

1 files changed, 7 insertions, 6 deletions

diff --git a/markdown/blockprocessors.py b/markdown/blockprocessors.py
index 1e6160f..3c320f8 100644
--- a/markdown/blockprocessors.py
+++ b/markdown/blockprocessors.py
@@ -499,7 +499,7 @@ class EmptyBlockProcessor(BlockProcessor):
 
     # Detect a block that only contains whitespace 
     # or only whitespace on the first line.
-    RE = re.compile(r'^\s*\n')
+    RE = re.compile(r'(^ *$)|(^ *\n)')
 
     def test(self, parent, block):
         return bool(self.RE.match(block))
@@ -508,13 +508,14 @@ class EmptyBlockProcessor(BlockProcessor):
         block = blocks.pop(0)
         m = self.RE.match(block)
         if m:
-            # Add remaining line to master blocks for later.
-            blocks.insert(0, block[m.end():])
+            theRest = block[m.end():]
+            if theRest:
+                # Add remaining lines to master blocks for later.
+                blocks.insert(0, theRest)
             sibling = self.lastChild(parent)
-            if sibling and sibling.tag == 'pre' and sibling[0] and \
-                    sibling[0].tag == 'code':
+            if sibling and sibling.tag == 'pre' and len(sibling) and sibling[0].tag == 'code':
                 # Last block is a codeblock. Append to preserve whitespace.
-                sibling[0].text = util.AtomicString('%s/n/n/n' % sibling[0].text )
+                sibling[0].text = util.AtomicString('%s\n' % sibling[0].text )
 
 
 class ParagraphProcessor(BlockProcessor):