php fatal error handler… failing with no error_get_last() set

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I have been using a fatal_handler() function that I expanded on for over a year now but for some reason I now have random errors popping up in the error_log file on the server and triggering the notification. Previous to a little while ago it was working fine. The errors seem to come from the array $error which is suppose

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As the name suggests, register_shutdown_function registers a handler to run every time PHP &#8220;shuts down&#8221; &#8211; that is, at the end of every request, regardless of whether it&#8217;s ending &#8220;normally&#8221; or after an error.It&#8217;s therefore up to you, inside the handler function, to detect whether the shutdown was due to a fatal error or not. The common trick with this is to look at the last &#8220;error&#8221;, which might better be termed &#8220;diagnostic&#8221;, because it includes Warnings, Notices, and Deprecation messages. If there was a fatal error, we can expect it to be the last thing that happened before the shutdown handler is called, so if we immediately call error_get_last, we should get the information about it.Let&#8217;s trace through some key parts of your function:// if nothing else sets $errno, assume that every request ends in a fatal error// that's probably not a sensible assumption (unless your code is really bad ????)$errno = E_CORE_ERROR; // ...// retrieve error information - will be NULL if no diagnostic has occurred$error = error_get_last();// add a 'user' key to the error information// this doesn't check if $error was NULL, so if it was, it will turn it into an array$error["user"] = $user["id"];// now check if $error is NULL - but it never will be, because of the line aboveif($error !== NULL) {    // take the error type from the array    // if it was actually NULL, this won't be set, so we'll get an $errno of NULL    // that's what's causing all the Notices in your logs    $errno   = $error["type"];    // ...}// after gathering the error information, decide whether to log itif(in_array($errno,$log_errors)) {Luckily, the default of E_CORE_ERROR and the broken check for NULL cancel each other out, so that if there was no error returned from error_get_last(), we are checking in_array(NULL,$log_errors), which will be false.However, looking at $log_errors, which is defined as a global variable earlier:$log_errors = array(                "E_ERROR" => 1,                "E_WARNING" => 2,                 "E_PARSE" => 4,                 "E_CORE_ERROR" => 16,                "E_USER_ERROR" => 256,                 "E_USER_WARNING" => 512,                 "E_USER_NOTICE" => 1024);Apart from the slightly odd decision to hard-code the numbers rather than use the actual constants, note that this includes both Warnings and Notices. These can happen at any time, and there might have been a dozen Notices already logged on the page, but error_get_last() will just contain the most recent if no other diagnostics happened afterwards. It&#8217;s therefore not relevant to look for these inside the shutdown handler &#8211; you just want to spot things that would cause a shutdown.A Notice or Warning will not cause a script to exit early, so it makes no sense to log them in a shutdown handler, which will only see whichever happened to come last. They will already have been logged based on your error_log settings, or you can use set_error_handler to have custom handling of all of them.We can massively simplify the function by checking for fatal errors (and only fatal errors) straight away, and just ending the function if none are found:function fatal_handler() {    $fatal_errors = [        E_ERROR,        E_USER_ERROR,        E_CORE_ERROR,        E_COMPILE_ERROR,        E_PARSE,        E_RECOVERABLE_ERROR    ];    $error = error_get_last();    if($error === NULL || !in_array($error['type'], $fatal_errors)) {       // Clean shutdown. Nothing to do.       return;    }    // Fatal error detected - proceed with logging based on value of $error    // ...}

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