trim leading newline char on blocks for html

org/testdata/blocks.html

@@ -22,6 +22,16 @@ block caption
 <div class="src src-text">
 <div class="highlight">
 <pre>
+a source block with leading newline, trailing newline characters
+and a line started
+  with leading space
+	and line leading tab.
+</pre>
+</div>
+</div>
+<div class="src src-text">
+<div class="highlight">
+<pre>
 a source block without a language
 </pre>
 </div>

org/testdata/blocks.org

@@ -12,6 +12,15 @@ function hello {
 hello
 #+END_SRC
 
+#+BEGIN_SRC
+
+a source block with leading newline, trailing newline characters
+and a line started
+  with leading space
+	and line leading tab.
+
+#+END_SRC
+
 #+BEGIN_SRC
 a source block without a language
 #+END_SRC

org/testdata/blocks.pretty_org

@@ -12,6 +12,15 @@ function hello {
 hello
 #+END_SRC
 
+#+BEGIN_SRC
+
+a source block with leading newline, trailing newline characters
+and a line started
+  with leading space
+	and line leading tab.
+
+#+END_SRC
+
 #+BEGIN_SRC
 a source block without a language
 #+END_SRC