6 files changed, 10 insertions, 7 deletions
diff --git a/system/helpers/captcha_helper.php b/system/helpers/captcha_helper.php
index a4383c9d3..3aac14db8 100644
--- a/system/helpers/captcha_helper.php
+++ b/system/helpers/captcha_helper.php
@@ -80,8 +80,7 @@ if ( ! function_exists('create_captcha'))
 		$current_dir = @opendir($img_path);
 		while ($filename = @readdir($current_dir))
 		{
-			if ($filename !== '.' && $filename !== '..' && $filename !== 'index.html'
-				&& (str_replace('.jpg', '', $filename) + $expiration) < $now)
+			if (substr($filename, -4) === '.jpg' && (str_replace('.jpg', '', $filename) + $expiration) < $now)
 			{
 				@unlink($img_path.$filename);
 			}
diff --git a/system/helpers/directory_helper.php b/system/helpers/directory_helper.php
index e7d3b5e8a..7d6b6770e 100644
--- a/system/helpers/directory_helper.php
+++ b/system/helpers/directory_helper.php
@@ -62,7 +62,7 @@ if ( ! function_exists('directory_map'))
 			while (FALSE !== ($file = readdir($fp)))
 			{
 				// Remove '.', '..', and hidden files [optional]
-				if ( ! trim($file, '.') OR ($hidden === FALSE && $file[0] === '.'))
+				if ($file === '.' OR $file === '..' OR ($hidden === FALSE && $file[0] === '.'))
 				{
 					continue;
 				}
diff --git a/system/helpers/download_helper.php b/system/helpers/download_helper.php
index 09c4de578..0232adfe4 100644
--- a/system/helpers/download_helper.php
+++ b/system/helpers/download_helper.php
@@ -95,7 +95,10 @@ if ( ! function_exists('force_download'))
 		}
 
 		// Clean output buffer
-		ob_clean();
+		if (ob_get_level() !== 0)
+		{
+			ob_clean();
+		}
 
 		// Generate the server headers
 		header('Content-Type: '.$mime);
diff --git a/system/helpers/html_helper.php b/system/helpers/html_helper.php
index 9843e804e..2372e8174 100644
--- a/system/helpers/html_helper.php
+++ b/system/helpers/html_helper.php
@@ -215,7 +215,7 @@ if ( ! function_exists('img'))
 			}
 		}
 
-		return $img._stringify_attributes($attributes).'/>';
+		return $img._stringify_attributes($attributes).' />';
 	}
 }
 
diff --git a/system/helpers/text_helper.php b/system/helpers/text_helper.php
index 8a1f01b51..b592f3cc0 100644
--- a/system/helpers/text_helper.php
+++ b/system/helpers/text_helper.php
@@ -89,7 +89,8 @@ if ( ! function_exists('character_limiter'))
 			return $str;
 		}
 
-		$str = preg_replace('/\s+/', ' ', str_replace(array("\r\n", "\r", "\n"), ' ', $str));
+		// a bit complicated, but faster than preg_replace with \s+
+		$str = preg_replace('/ {2,}/', ' ', str_replace(array("\r", "\n", "\t", "\x0B", "\x0C"), ' ', $str));
 
 		if (strlen($str) <= $n)
 		{
diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 57208c948..b1f5eccf1 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -534,7 +534,7 @@ if ( ! function_exists('redirect'))
 		}
 
 		// IIS environment likely? Use 'refresh' for better compatibility
-		if (DIRECTORY_SEPARATOR !== '/' && $method === 'auto')
+		if ($method === 'auto' && isset($_SERVER['SERVER_SOFTWARE']) && strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS') !== FALSE)
 		{
 			$method = 'refresh';
 		}