Add support for protocol-relative URLs in HTML helpers img(), link_tag()
diff --git a/system/helpers/html_helper.php b/system/helpers/html_helper.php
index 239f24c..d8c3e6d 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -181,7 +181,7 @@
 
 		foreach ($src as $k => $v)
 		{
-			if ($k === 'src' && ! preg_match('#^https?://#i', $v))
+			if ($k === 'src' && ! preg_match('#^([a-z]+:)?//#i', $v))
 			{
 				if ($index_page === TRUE)
 				{
@@ -273,7 +273,7 @@
 		{
 			foreach ($href as $k => $v)
 			{
-				if ($k === 'href' && strpos($v, '://') === FALSE)
+				if ($k === 'href' && ! preg_match('#^([a-z]+:)?//#i', $v))
 				{
 					if ($index_page === TRUE)
 					{
@@ -292,7 +292,7 @@
 		}
 		else
 		{
-			if (strpos($href, '://') !== FALSE)
+			if ( ! preg_match('#^([a-z]+:)?//#i', $href))
 			{
 				$link .= 'href="'.$href.'" ';
 			}