From 8a9058621824ff0a675a735fbbf1c1161d596208 Mon Sep 17 00:00:00 2001
From: Nathan Baulch <nathan.baulch@gmail.com>
Date: Thu, 29 Mar 2018 22:10:30 +1100
Subject: [PATCH] Support #hashtag per CommonMark and GFM specs

---
 Parsedown.php              | 5 +++++
 test/data/atx_heading.html | 4 +++-
 test/data/atx_heading.md   | 6 +++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Parsedown.php b/Parsedown.php
index 382023c..1578815 100644
--- a/Parsedown.php
+++ b/Parsedown.php
@@ -519,6 +519,11 @@ class Parsedown
             }
 
             $text = trim($Line['text'], '#');
+
+            if (!isset($text[0]) or $text[0] !== ' ') {
+                return;
+            }
+
             $text = trim($text, ' ');
 
             $Block = array(
diff --git a/test/data/atx_heading.html b/test/data/atx_heading.html
index 94c3825..545d889 100644
--- a/test/data/atx_heading.html
+++ b/test/data/atx_heading.html
@@ -7,5 +7,7 @@
 <p>####### not a heading</p>
 <h1>closed h1</h1>
 <p>#</p>
+<p>##</p>
 <h1># of levels</h1>
-<h1># of levels #</h1>
\ No newline at end of file
+<h1># of levels #</h1>
+<p>#hashtag</p>
\ No newline at end of file
diff --git a/test/data/atx_heading.md b/test/data/atx_heading.md
index 62fdd6c..7748aa9 100644
--- a/test/data/atx_heading.md
+++ b/test/data/atx_heading.md
@@ -16,6 +16,10 @@
 
 #
 
+##
+
 # # of levels
 
-# # of levels # #
\ No newline at end of file
+# # of levels # #
+
+#hashtag
\ No newline at end of file