core-bundle/src/Resources/contao/library/Contao/Config.php
protected function markModified()
	{
		// Return if marked as modified already
		if ($this->blnIsModified === true)
		{
			return;
		}

		$this->blnIsModified = true;

		// Reset the top and bottom content (see #344)
		$this->strTop = '';
		$this->strBottom = '';

		// Import the Files object (required in the destructor)
		$this->Files = Files::getInstance();

		// Parse the local configuration file
		if (static::$blnHasLcf)
		{
			$strMode = 'top';
			$resFile = fopen($this->strRootDir . '/system/config/localconfig.php', 'rb');

			while (!feof($resFile))
			{
				$strLine = fgets($resFile);
				$strTrim = trim($strLine);

				if ($strTrim == '?>')
				{
					continue;
				}

				if ($strTrim == '### INSTALL SCRIPT START ###')
				{
					$strMode = 'data';
					continue;
				}

				if ($strTrim == '### INSTALL SCRIPT STOP ###')
				{
					$strMode = 'bottom';
					continue;
				}

				if ($strMode == 'top')
				{
					$this->strTop .= $strLine;
				}
				elseif ($strMode == 'bottom')
				{
					$this->strBottom .= $strLine;
				}
				elseif ($strTrim != '')
				{
					$arrChunks = array_map('trim', explode('=', $strLine, 2));
					$this->arrData[$arrChunks[0]] = $arrChunks[1];
				}
			}

			fclose($resFile);
		}
	}
protected function markModified()
	{
		// Return if marked as modified already
		if ($this->blnIsModified === true)
		{
			return;
		}

		$this->blnIsModified = true;

		// Reset the top and bottom content (see #344)
		$this->strTop = '';
		$this->strBottom = '';

		// Import the Files object (required in the destructor)
		$this->Files = Files::getInstance();

		// Parse the local configuration file
		if (static::$blnHasLcf)
		{
			$strMode = 'top';
			$resFile = fopen($this->strRootDir . '/system/config/localconfig.php', 'rb');

			while (!feof($resFile))
			{
				$strLine = fgets($resFile);
				$strTrim = trim($strLine);

				if ($strTrim == '?>')
				{
					continue;
				}

				if ($strTrim == '### INSTALL SCRIPT START ###')
				{
					$strMode = 'data';
					continue;
				}

				if ($strTrim == '### INSTALL SCRIPT STOP ###')
				{
					$strMode = 'bottom';
					continue;
				}

				if ($strMode == 'top')
				{
					$this->strTop .= $strLine;
				}
				elseif ($strMode == 'bottom')
				{
					$this->strBottom .= $strLine;
				}
				elseif ($strTrim != '')
				{
					$arrChunks = array_map('trim', explode('=', $strLine, 2));
					$this->arrData[$arrChunks[0]] = $arrChunks[1];
				}
			}

			fclose($resFile);
		}
	}
Mark the object as modified