Steps to reproduce
1. I have created a shared folder Sub in a shared folder Top.
2. I create a shared link with password on Top.
3. I create a shared link with password on Sub.
Both 2 and 3 should show the files shared after having entered the correct password.
2. Shows the shared files.
3. Shows a 500 error. The logs show 'AH01067: Failed to read FastCGI header'
Operating system: Centos 6.7
Web server: Apache 2.4
Database: MariaDB 10
PHP version: 5.6.25
ownCloud version (see ownCloud admin page): 9.1.1
Updated from an older ownCloud or fresh install: Updated from 9.1