[php-src] Issue #7875: mail() logging might be unsafe in combination with an error handler converting errors into exceptions

Issue: https://github.com/php/php-src/issues/7875 Comment Author: TimWolla It is correct that this issue would not happen with the error handler converting the warning into an Exception. However an error handler like that certainly is nothing out of the usual. In fact such an error handler [is an example within the official PHP manual](https://www.php.net/manual/en/class.errorexception.php#errorexception.example.error-handler) (that's the source of the error handler in my example script). Large Frameworks such as Laravel also use an error handler similar to our error handler: https://github.com/laravel/framework/blob/fada7461eca5e2719b81894219da52b11724dd6d/src/Illuminate/Foundation/Bootstrap/HandleExceptions.php#L68-L76. In many cases it is helpful to treat PHP warnings and notices as exceptions, because they indicate some programming error more often than not. However this issue would not happen if this error handler would actually throw the exception and thus abort execution at the place where the warning is emitted, instead of proceeding with the execution of the native function and only then throwing the exception. This is a behavior that differs from userland functions [1] and certainly is unexpected. There's also no easy way to work around this issue, except switching out the error handler before calling mail(). [1] I understand why that might be: The error handler itself might call mail() while one call to mail() already is in progress.