2 files changed, 19 insertions, 7 deletions
diff --git a/phpBB/download/file.php b/phpBB/download/file.php
index eee2090da0..2675165cb9 100644
--- a/phpBB/download/file.php
+++ b/phpBB/download/file.php
@@ -279,7 +279,7 @@ else if ($download_id)
 		phpbb_increment_downloads($db, $attachment['attach_id']);
 	}
 
-	if ($display_cat == ATTACHMENT_CATEGORY_IMAGE && $mode === 'view' && (strpos($attachment['mimetype'], 'image') === 0) && ((strpos(strtolower($user->browser), 'msie') !== false) && (strpos(strtolower($user->browser), 'msie 8.0') === false)))
+	if ($display_cat == ATTACHMENT_CATEGORY_IMAGE && $mode === 'view' && (strpos($attachment['mimetype'], 'image') === 0) && !phpbb_is_greater_ie7($user->browser))
 	{
 		wrap_img_in_html(append_sid($phpbb_root_path . 'download/file.' . $phpEx, 'id=' . $attachment['attach_id']), $attachment['real_filename']);
 		file_gc();
diff --git a/phpBB/includes/functions_download.php b/phpBB/includes/functions_download.php
index 9ae647d806..949c47487b 100644
--- a/phpBB/includes/functions_download.php
+++ b/phpBB/includes/functions_download.php
@@ -46,7 +46,7 @@ function send_avatar_to_browser($file, $browser)
 		$image_data = @getimagesize($file_path);
 		header('Content-Type: ' . image_type_to_mime_type($image_data[2]));
 
-		if (strpos(strtolower($browser), 'msie') !== false && strpos(strtolower($browser), 'msie 8.0') === false)
+		if (!phpbb_is_greater_ie7($browser))
 		{
 			header('Content-Disposition: attachment; ' . header_filename($file));
 
@@ -174,10 +174,9 @@ function send_file_to_browser($attachment, $upload_dir, $category)
 	header('Pragma: public');
 
 	// Send out the Headers. Do not set Content-Disposition to inline please, it is a security measure for users using the Internet Explorer.
-	$is_ie8 = (strpos(strtolower($user->browser), 'msie 8.0') !== false);
 	header('Content-Type: ' . $attachment['mimetype']);
 
-	if ($is_ie8)
+	if (phpbb_is_greater_ie7($user->browser))
 	{
 		header('X-Content-Type-Options: nosniff');
 	}
@@ -189,7 +188,7 @@ function send_file_to_browser($attachment, $upload_dir, $category)
 	}
 	else
 	{
-		if (empty($user->browser) || (!$is_ie8 && (strpos(strtolower($user->browser), 'msie') !== false)))
+		if (empty($user->browser) || !phpbb_is_greater_ie7($user->browser))
 		{
 			header('Content-Disposition: attachment; ' . header_filename(htmlspecialchars_decode($attachment['real_filename'])));
 			if (empty($user->browser) || (strpos(strtolower($user->browser), 'msie 6.0') !== false))
@@ -200,7 +199,7 @@ function send_file_to_browser($attachment, $upload_dir, $category)
 		else
 		{
 			header('Content-Disposition: ' . ((strpos($attachment['mimetype'], 'image') === 0) ? 'inline' : 'attachment') . '; ' . header_filename(htmlspecialchars_decode($attachment['real_filename'])));
-			if ($is_ie8 && (strpos($attachment['mimetype'], 'image') !== 0))
+			if (phpbb_is_greater_ie7($user->browser) && (strpos($attachment['mimetype'], 'image') !== 0))
 			{
 				header('X-Download-Options: noopen');
 			}
@@ -410,7 +409,8 @@ function set_modified_headers($stamp, $browser)
 
 	// let's see if we have to send the file at all
 	$last_load 	=  $request->header('Modified-Since') ? strtotime(trim($request->header('Modified-Since'))) : false;
-	if ((strpos(strtolower($browser), 'msie 6.0') === false) && (strpos(strtolower($browser), 'msie 8.0') === false))
+
+	if (strpos(strtolower($browser), 'msie 6.0') === false && !phpbb_is_greater_ie7($browser))
 	{
 		if ($last_load !== false && $last_load >= $stamp)
 		{
@@ -721,3 +721,15 @@ function phpbb_download_clean_filename($filename)
 
 	return $filename;
 }
+
+/**
+* Check if the browser is internet explorer version 7+
+*
+* @param string $user_agent	User agent HTTP header
+*
+* @return bool true if internet explorer version is greater than 7
+*/
+function phpbb_is_greater_ie7($user_agent)
+{
+	return (bool) preg_match('/msie [^67]+\\.*;/', strtolower($user_agent));
+}