Index: branches/5.2.x/core/kernel/utility/debugger.php
===================================================================
--- branches/5.2.x/core/kernel/utility/debugger.php
+++ branches/5.2.x/core/kernel/utility/debugger.php
@@ -1881,6 +1881,9 @@
 					$this->_fatalErrorHash = $this->_getErrorHash($errfile, $errline);
 					$this->appendTrace(4);
 				}
+				elseif ( !kLogger::isErrorOriginAllowed($errfile) ) {
+					return;
+				}
 
 				$this->expandError($errstr, $errfile, $errline);
 
Index: branches/5.2.x/core/kernel/utility/logger.php
===================================================================
--- branches/5.2.x/core/kernel/utility/logger.php
+++ branches/5.2.x/core/kernel/utility/logger.php
@@ -734,15 +734,29 @@
 	/**
 	 * Writes prepared log to database or disk, when database isn't available
 	 *
-	 * @param int $storage_medium
-	 * @return bool|int
-	 * @access public
-	 * @throws InvalidArgumentException
+	 * @param integer $storage_medium Storage medium.
+	 * @param boolean $check_origin   Check error origin.
+	 *
+	 * @return integer|boolean
+	 * @throws InvalidArgumentException When unknown storage medium is given.
 	 */
-	public function write($storage_medium = self::LS_AUTOMATIC)
+	public function write($storage_medium = self::LS_AUTOMATIC, $check_origin = false)
 	{
-		if ( !$this->_logRecord || $this->_logRecord['LogLevel'] > $this->_maxLogLevel || $this->_state == self::STATE_DISABLED ) {
-			// nothing to save OR less detailed logging requested OR disabled
+		if ( $check_origin && isset($this->_logRecord['LogSourceFilename']) ) {
+			$origin_allowed = self::isErrorOriginAllowed($this->_logRecord['LogSourceFilename']);
+		}
+		else {
+			$origin_allowed = true;
+		}
+
+		if ( !$this->_logRecord
+			|| $this->_logRecord['LogLevel'] > $this->_maxLogLevel
+			|| !$origin_allowed
+			|| $this->_state == self::STATE_DISABLED
+		) {
+			// Nothing to save OR less detailed logging requested OR origin not allowed OR disabled.
+			$this->_logRecord = array();
+
 			return false;
 		}
 
@@ -1057,6 +1071,49 @@
 	}
 
 	/**
+	 * Determines if error should be logged based on it's origin.
+	 *
+	 * @param string $file File.
+	 *
+	 * @return boolean
+	 */
+	public static function isErrorOriginAllowed($file)
+	{
+		static $error_origin_regexp;
+
+		// Lazy detect error origins, because they're not available at construction time.
+		if ( !$error_origin_regexp ) {
+			$error_origins = array();
+			$application = kApplication::Instance();
+
+			foreach ( $application->ModuleInfo as $module_info ) {
+				$error_origins[] = preg_quote(rtrim($module_info['Path'], '/'), '/');
+			}
+
+			$error_origins = array_unique($error_origins);
+			$error_origin_regexp = '/^' . preg_quote(FULL_PATH, '/') . '\/(' . implode('|', $error_origins) . ')\//';
+		}
+
+		// Allow dynamically generated code.
+		if ( strpos($file, 'eval()\'d code') !== false ) {
+			return true;
+		}
+
+		// Allow known modules.
+		if ( preg_match('/^' . preg_quote(MODULES_PATH, '/') . '\//', $file) ) {
+			return preg_match($error_origin_regexp, $file) == 1;
+		}
+
+		// Don't allow Vendors.
+		if ( preg_match('/^' . preg_quote(FULL_PATH, '/') . '\/vendor\//', $file) ) {
+			return false;
+		}
+
+		// Allow everything else within main folder.
+		return preg_match('/^' . preg_quote(FULL_PATH, '/') . '\//', $file) == 1;
+	}
+
+	/**
 	 * Parses database error message into error number, error message and sql that caused that error
 	 *
 	 * @static
@@ -1165,6 +1222,13 @@
 		$this->_handlers[] = $handler;
 	}
 
+	/**
+	 * Returns `true`, when no other error handlers should process this error.
+	 *
+	 * @param integer $errno Error code.
+	 *
+	 * @return boolean
+	 */
 	protected function _handleFatalError($errno)
 	{
 		$debug_mode = defined('DEBUG_MODE') && DEBUG_MODE;
@@ -1182,7 +1246,7 @@
 			}
 		}
 
-		return null;
+		return false;
 	}
 
 	/**
@@ -1304,12 +1368,12 @@
 		$log = $this->_logger->prepare()->addError($errno, $errstr, $errfile, $errline);
 
 		if ( $this->_handleFatalError($errno) ) {
-			$log->write();
+			$log->write(kLogger::LS_AUTOMATIC, !$this->_isFatalError($errno));
 
 			return true;
 		}
 
-		$log->write();
+		$log->write(kLogger::LS_AUTOMATIC, !$this->_isFatalError($errno));
 
 		$res = false;