Index: typo3/sysext/cms/tslib/class.tslib_fe.php
===================================================================
--- typo3/sysext/cms/tslib/class.tslib_fe.php	(revision 7919)
+++ typo3/sysext/cms/tslib/class.tslib_fe.php	(working copy)
@@ -499,6 +499,9 @@
 		if ($link !== FALSE) {
 			if (!TYPO3_db)	{
 				$this->printError('No database selected','Database Error');
+					// Allow temporary access to 1-2-3 mode in Install Tool
+				touch(PATH_typo3conf . 'ENABLE_INSTALL_TOOL');
+				t3lib_div::fixPermissions(PATH_typo3conf . 'ENABLE_INSTALL_TOOL');
 					// Redirects to the Install Tool:
 				echo '<script type="text/javascript">
 						/*<![CDATA[*/
@@ -519,6 +522,9 @@
 			}
 		} else {
 			if (!TYPO3_db)	{
+					// Allow temporary access to 1-2-3 mode in Install Tool
+				touch(PATH_typo3conf . 'ENABLE_INSTALL_TOOL');
+				t3lib_div::fixPermissions(PATH_typo3conf . 'ENABLE_INSTALL_TOOL');
 					// Redirects to the Install Tool:
 				echo '<script type="text/javascript">
 						/*<![CDATA[*/