Stupid PHP Warnings because of headers()

[SNo0py]

A lot of times I find
PHP Warning: Cannot modify header information - headers already sent in...
in the logs. This can easily be avoided by adding

if(!headers_sent())

before the header() call (i.e. in program/include/rcube_shared.inc on line 154!).

This is just a workaround, ideally the code is written in a way so it does not send headers just in the middle of the code. But at least get rid of the warnings!

[thomasb]

There should be no output before the script terminates. Those errors are mostly caused by included localization files that have an UTF-8 BOM or other whitespace. Instead of adding this workaround we have to find the files causing those errors.

[thomasb]

Duplicate of ticket #1483926