[TYPO3-core] RFC #9355: Add an error and exception handler (backported from FLOW3)

[Rupert Germann]

Oliver Hader schrieb:
...
  > Concerning the performance issues:
> I agree with Rupert that it's not required to load the error-/exception
> handler in any case. But if an error or exception occurs it should be
> handled somehow.

hmm, on my server errors are handled by "display_errors=Off" in php.ini.
If I disable errors in install tool and in php.ini I'd be surprised to 
see a message from the exceptionhandler.

besides this there's also a serious performance problem with the current 
implementation.

my results for delivering cached pages:
trunk: 			 307.19 trans/sec  100% 	
with exception handling: 280.13 trans/sec   91%

9% performance loss for not displaying any error message?!

My production sites doesn't produce errors or exceptions - if I want to 
have access to values or states that were handled during execution of a 
piece of code I use the devlog.

So I (and probably others) will not have any benefit from the exception 
handling in its current state - it will only slow things down.

simply wrapping the initialisation of the exception handler in a 
condition which checks if $TYPO3_CONF_VARS['SYS']['displayErrors'] is 1 
or 2 would be the solution.

greets
rueprt