Don't silence fatal errors with @

[nikic]

When the silencing operator @ is used, the intention is generally to silence expected warnings or notices. However, it currently also silences fatal errors. As fatal errors also abort request execution, the result will often be a hard to debug white screen of death.

This patch changes the behavior of @ to only silence warnings, notices and other low-level diagnostics. The following error types will no longer be silenced:

• E_ERROR
• E_CORE_ERROR
• E_COMPILE_ERROR
• E_USER_ERROR
• E_RECOVERABLE_ERROR
• E_PARSE

There are two main implications for backwards compatibility:

• Code that legitimately wants to silence fatal errors for whatever reason should now use error_reporting() (or ini_set()) to do so.
• Error handlers that want to only handle non-silenced errors may have to be adjusted. A common pattern I found in our own tests if checks for error_reporting() != 0 to detect silencing. This should be changed to error_reporting() & $err_no to detect whether the specific error type is silenced.

[krakjoe]

Merged as 839bdf1

Thanks.

[nikic]

Sorry, this wasn't ready for merging yet, because more tests need to be fixed. I've reverted for now.

[nikic]

Merged as a302d11.