X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2Fexception%2FMWExceptionHandler.php;h=b4e483bf53289f935f3d49a94b78d53f60fd1c9d;hb=e390198c4e4be7632b01173e42050061f1cc346a;hp=bd823b5e07c3ea6f6052518fb7fc27eb4fb3be61;hpb=0e56ff447bbb74df007f2573725baaa61ed2745c;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/exception/MWExceptionHandler.php b/includes/exception/MWExceptionHandler.php
index bd823b5e07..b4e483bf53 100644
--- a/includes/exception/MWExceptionHandler.php
+++ b/includes/exception/MWExceptionHandler.php
@@ -35,12 +35,35 @@ class MWExceptionHandler {
 	 * @var string $reservedMemory
 	 */
 	protected static $reservedMemory;
+
 	/**
+	 * Error types that, if unhandled, are fatal to the request.
+	 *
+	 * On PHP 7, these error types may be thrown as Error objects, which
+	 * implement Throwable (but not Exception).
+	 *
+	 * On HHVM, these invoke the set_error_handler callback, similar to how
+	 * (non-fatal) warnings and notices are reported, except that after this
+	 * handler runs for fatal error tpyes, script execution stops!
+	 *
+	 * The user will be shown an HTTP 500 Internal Server Error.
+	 * As such, these should be sent to MediaWiki's "fatal" or "exception"
+	 * channel. Normally, the error handler logs them to the "error" channel.
+	 *
 	 * @var array $fatalErrorTypes
 	 */
 	protected static $fatalErrorTypes = [
-		E_ERROR, E_PARSE, E_CORE_ERROR, E_COMPILE_ERROR, E_USER_ERROR,
-		/* HHVM's FATAL_ERROR level */ 16777217,
+		E_ERROR,
+		E_PARSE,
+		E_CORE_ERROR,
+		E_COMPILE_ERROR,
+		E_USER_ERROR,
+
+		// E.g. "Catchable fatal error: Argument X must be Y, null given"
+		E_RECOVERABLE_ERROR,
+
+		// HHVM's FATAL_ERROR constant
+		16777217,
 	];
 	/**
 	 * @var bool $handledFatalCallback
@@ -51,9 +74,32 @@ class MWExceptionHandler {
 	 * Install handlers with PHP.
 	 */
 	public static function installHandler() {
+		// This catches:
+		// * Exception objects that were explicitly thrown but not
+		//   caught anywhere in the application. This is rare given those
+		//   would normally be caught at a high-level like MediaWiki::run (index.php),
+		//   api.php, or ResourceLoader::respond (load.php). These high-level
+		//   catch clauses would then call MWExceptionHandler::logException
+		//   or MWExceptionHandler::handleException.
+		//   If they are not caught, then they are handled here.
+		// * Error objects (on PHP 7+), for issues that would historically
+		//   cause fatal errors but may now be caught as Throwable (not Exception).
+		//   Same as previous case, but more common to bubble to here instead of
+		//   caught locally because they tend to not be safe to recover from.
+		//   (e.g. argument TypeErorr, devision by zero, etc.)
 		set_exception_handler( 'MWExceptionHandler::handleUncaughtException' );
+
+		// This catches:
+		// * Non-fatal errors (e.g. PHP Notice, PHP Warning, PHP Error) that do not
+		//   interrupt execution in any way. We log these in the background and then
+		//   continue execution.
+		// * Fatal errors (on HHVM in PHP5 mode) where PHP 7 would throw Throwable.
 		set_error_handler( 'MWExceptionHandler::handleError' );
 
+		// This catches:
+		// * Fatal error for which no Throwable is thrown (PHP 7), and no Error emitted (HHVM).
+		//   This includes Out-Of-Memory and Timeout fatals.
+		//
 		// Reserve 16k of memory so we can report OOM fatals
 		self::$reservedMemory = str_repeat( ' ', 16384 );
 		register_shutdown_function( 'MWExceptionHandler::handleFatalError' );
@@ -192,10 +238,6 @@ class MWExceptionHandler {
 		// behaviour given the null was not part of the code and is likely not
 		// accounted for.
 		switch ( $level ) {
-			case E_RECOVERABLE_ERROR:
-				$levelName = 'Error';
-				$severity = LogLevel::ERROR;
-				break;
 			case E_WARNING:
 			case E_CORE_WARNING:
 			case E_COMPILE_WARNING:
@@ -206,8 +248,12 @@ class MWExceptionHandler {
 				$levelName = 'Notice';
 				$severity = LogLevel::ERROR;
 				break;
-			case E_USER_WARNING:
 			case E_USER_NOTICE:
+				// Used by wfWarn(), MWDebug::warning()
+				$levelName = 'Notice';
+				$severity = LogLevel::WARNING;
+				break;
+			case E_USER_WARNING:
 				// Used by wfWarn(), MWDebug::warning()
 				$levelName = 'Warning';
 				$severity = LogLevel::WARNING;
@@ -231,9 +277,9 @@ class MWExceptionHandler {
 		self::logError( $e, 'error', $severity );
 
 		// If $wgPropagateErrors is true return false so PHP shows/logs the error normally.
-		// Ignore $wgPropagateErrors if the error should break execution, or track_errors is set
+		// Ignore $wgPropagateErrors if track_errors is set
 		// (which means someone is counting on regular PHP error handling behavior).
-		return !( $wgPropagateErrors || $level == E_RECOVERABLE_ERROR || ini_get( 'track_errors' ) );
+		return !( $wgPropagateErrors || ini_get( 'track_errors' ) );
 	}
 
 	/**
@@ -439,22 +485,6 @@ TXT;
 		}, $trace );
 	}
 
-	/**
-	 * Get the ID for this exception.
-	 *
-	 * The ID is saved so that one can match the one output to the user (when
-	 * $wgShowExceptionDetails is set to false), to the entry in the debug log.
-	 *
-	 * @since 1.22
-	 * @deprecated since 1.27: Exception IDs are synonymous with request IDs.
-	 * @param Exception|Throwable $e
-	 * @return string
-	 */
-	public static function getLogId( $e ) {
-		wfDeprecated( __METHOD__, '1.27' );
-		return WebRequest::getRequestId();
-	}
-
 	/**
 	 * If the exception occurred in the course of responding to a request,
 	 * returns the requested URL. Otherwise, returns false.