From 4cd2078e7a4f48f191b3568886b3074365dd10a9 Mon Sep 17 00:00:00 2001
From: facelessuser <faceless.shop@gmail.com>
Date: Mon, 23 Jan 2017 23:23:22 -0700
Subject: [PATCH] Fix HTML parse with empty lines

If both open and close was not found in first block, additional blocks
were evaluated without context of previous blocks.  The algorithm needs
to evaluate a buffer with the left bracket present.  So feed in all
items and get the right bracket, then adjust the data_index to be
relative to the last block.
---
 markdown/preprocessors.py |  8 +++++++-
 tests/misc/html.html      | 11 +++++++++++
 tests/misc/html.txt       | 11 +++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/markdown/preprocessors.py b/markdown/preprocessors.py
index 7ea4fcf9f..94f983005 100644
--- a/markdown/preprocessors.py
+++ b/markdown/preprocessors.py
@@ -258,7 +258,13 @@ def run(self, lines):
             else:
                 items.append(block)
 
-                right_tag, data_index = self._get_right_tag(left_tag, 0, block)
+                # Need to evaluate all items so we can calculate relative to the left index.
+                right_tag, data_index = self._get_right_tag(left_tag, left_index, ''.join(items))
+                # Adjust data_index: relative to items -> relative to last block
+                prev_block_length = 0
+                for item in items[:-1]:
+                    prev_block_length += len(item)
+                data_index -= prev_block_length
 
                 if self._equal_tags(left_tag, right_tag):
                     # if find closing tag
diff --git a/tests/misc/html.html b/tests/misc/html.html
index 1eb6a9729..5380bbdc2 100644
--- a/tests/misc/html.html
+++ b/tests/misc/html.html
@@ -8,6 +8,17 @@ <h1>Block level html</h1>
 Html with various attributes.
 </div>
 
+<div>
+    <div>
+        Div with a blank line
+
+        in the middle.
+    </div>
+    <div>
+        This gets treated as HTML.
+    </div>
+</div>
+
 <p>And of course <script>blah</script>.</p>
 <p><a href="script&gt;stuff&lt;/script">this <script>link</a></p>
 <p>Some funky <x\]> inline stuff with markdown escaping syntax.</p>
diff --git a/tests/misc/html.txt b/tests/misc/html.txt
index dfee68ddf..8f18fa7a7 100644
--- a/tests/misc/html.txt
+++ b/tests/misc/html.txt
@@ -11,6 +11,17 @@ Now some <arbitrary>arbitrary tags</arbitrary>.
 Html with various attributes.
 </div>
 
+<div>
+    <div>
+        Div with a blank line
+
+        in the middle.
+    </div>
+    <div>
+        This gets treated as HTML.
+    </div>
+</div>
+
 And of course <script>blah</script>.
 
 [this <script>link](<script>stuff</script>)