[horde] Strange loop when configuring Horde

[Luciano Ramalho]

Steps to reproduce:

a) following instructions in horde/docs/INSTALL, follow steps in 
Configuring Horde through item "5. Completing Configuration".

b) in a shell, go to the horde/config directory and to chmod a+w 
conf.php (conf.php was copied from conf.php.dist in a previous step).

c) visit http://localhost/horde/ and click on Administration->Setup on 
the left panel and then on the Horde (horde) link in the 
Application-Status table.

d) you may configure at will, or not at all; however, when you click on 
the [Generate Horde Configuration] button, the redirect loop starts and 
lasts several minutes; when it ends, only the left panel is showing

I've done this procedure at least three times. On step (d) initially I 
did configure many options under the several settings tabs, and thought 
I had done something wrong there. A second time I configured less 
things, to be safer, but hit the same bug. A third time I did not touch 
any tabs, to verify that the bug does not depend on choices I had made.

Step (b) is critical to reproduce. If the file is not writable, Horde 
behaves as expected.

Cheers,

Luciano