diff --git a/phpBB/adm/style/acp_board.html b/phpBB/adm/style/acp_board.html
index 64592a5de2..04dee98276 100644
--- a/phpBB/adm/style/acp_board.html
+++ b/phpBB/adm/style/acp_board.html
@@ -18,10 +18,11 @@
 <!-- BEGIN options -->
 	<!-- IF options.S_LEGEND -->
 		<!-- IF not options.S_FIRST_ROW -->
-			</fieldset>
-		<!-- ENDIF -->
+		</fieldset>
+
 		<fieldset>
-			<legend>{options.LEGEND}</legend>
+		<!-- ENDIF -->
+		<legend>{options.LEGEND}</legend>
 	<!-- ELSE -->
 
 		<dl>
diff --git a/phpBB/adm/style/installer_form.html b/phpBB/adm/style/installer_form.html
index cc5b041fa1..a38f33c7c2 100644
--- a/phpBB/adm/style/installer_form.html
+++ b/phpBB/adm/style/installer_form.html
@@ -49,7 +49,7 @@
 <fieldset class="submit-buttons">
 	<legend>{L_SUBMIT}</legend>
 	<!-- BEGIN submit_buttons -->
-	<input class="button1" type="submit" name="{submit_buttons.KEY}" value="{submit_buttons.TITLE}" />
+	<input class="button1<!-- IF submit_buttons.DISABLED --> disabled<!-- ENDIF -->" type="submit" name="{submit_buttons.KEY}" value="{submit_buttons.TITLE}"<!-- IF submit_buttons.DISABLED --> disabled="disabled"<!-- ENDIF --> />
 	<!-- END submit_buttons -->
 </fieldset>
 <!-- ENDIF -->
diff --git a/phpBB/phpbb/install/helper/iohandler/ajax_iohandler.php b/phpBB/phpbb/install/helper/iohandler/ajax_iohandler.php
index a40d457466..bce0149890 100644
--- a/phpBB/phpbb/install/helper/iohandler/ajax_iohandler.php
+++ b/phpBB/phpbb/install/helper/iohandler/ajax_iohandler.php
@@ -186,6 +186,7 @@ class ajax_iohandler extends iohandler_base
 			$tpl_ary['TITLE'] = $this->language->lang($input_options['label']);
 			$tpl_ary['KEY'] = $input_name;
 			$tpl_ary['S_EXPLAIN'] = false;
+			$tpl_ary['DISABLED'] = isset($input_options['disabled']) ? $input_options['disabled'] : false;
 
 			if (isset($input_options['default']))
 			{
@@ -219,6 +220,11 @@ class ajax_iohandler extends iohandler_base
 
 		$this->template->assign_var('S_NOT_ONLY_BUTTON_FORM', $not_button_form);
 
+		if (!$not_button_form)
+		{
+			$this->template->destroy_block_vars('options');
+		}
+
 		$this->template->set_filenames(array(
 			'form_install' => 'installer_form.html',
 		));
diff --git a/phpBB/phpbb/install/module/update_filesystem/task/download_updated_files.php b/phpBB/phpbb/install/module/update_filesystem/task/download_updated_files.php
index f911b7ac62..21aa93b7ea 100644
--- a/phpBB/phpbb/install/module/update_filesystem/task/download_updated_files.php
+++ b/phpBB/phpbb/install/module/update_filesystem/task/download_updated_files.php
@@ -78,16 +78,23 @@ class download_updated_files extends task_base
 		}
 		else if ($this->iohandler->get_input('update_recheck_files_submit', false))
 		{
+			$this->installer_config->set('file_updater_elem_progress', '');
+			$this->installer_config->set('update_files', array());
 			throw new jump_to_restart_point_exception('check_update_files');
 		}
 		else
 		{
-			// Render download box
-			$this->iohandler->add_download_link(
-				'phpbb_installer_update_file_download',
-				'DOWNLOAD_UPDATE_METHOD',
-				'DOWNLOAD_UPDATE_METHOD_EXPLAIN'
-			);
+			$file_update_info = $this->installer_config->get('update_files', array());
+
+			if (count($file_update_info) > 0)
+			{
+				// Render download box
+				$this->iohandler->add_download_link(
+					'phpbb_installer_update_file_download',
+					'DOWNLOAD_UPDATE_METHOD',
+					'DOWNLOAD_UPDATE_METHOD_EXPLAIN'
+				);
+			}
 
 			// Add form to continue update
 			$this->iohandler->add_user_form_group('UPDATE_CONTINUE_UPDATE_PROCESS', array(
@@ -96,8 +103,9 @@ class download_updated_files extends task_base
 					'type'	=> 'submit',
 				),
 				'database_update_submit'	=> array(
-					'label'	=> 'UPDATE_CONTINUE_UPDATE_PROCESS',
-					'type'	=> 'submit',
+					'label'		=> 'UPDATE_CONTINUE_UPDATE_PROCESS',
+					'type'		=> 'submit',
+					'disabled'	=> count($file_update_info) > 0,
 				),
 			));
 
diff --git a/phpBB/phpbb/install/module/update_filesystem/task/file_check.php b/phpBB/phpbb/install/module/update_filesystem/task/file_check.php
index 47a71eb844..9daa8530c6 100644
--- a/phpBB/phpbb/install/module/update_filesystem/task/file_check.php
+++ b/phpBB/phpbb/install/module/update_filesystem/task/file_check.php
@@ -103,6 +103,29 @@ class file_check extends task_base
 			$file_update_info = array();
 			$file_update_info['update_without_diff'] = array_diff($update_info['binary'], $update_info['deleted']);
 
+			foreach ($file_update_info['update_without_diff'] as $key => $binary_file)
+			{
+				$new_file = $new_path . $binary_file;
+				$file = $this->phpbb_root_path . $binary_file;
+
+				if (!$this->filesystem->exists($file))
+				{
+					continue;
+				}
+
+				if (md5_file($file) === md5_file($new_file))
+				{
+					// File already up to date
+					unset($file_update_info['update_without_diff'][$key]);
+				}
+			}
+
+			// Remove update without diff info if empty
+			if (count($file_update_info['update_without_diff']) < 1)
+			{
+				unset($file_update_info['update_without_diff']);
+			}
+
 			// Filter out files that are already deleted
 			$file_update_info['delete'] = array_filter(
 				$update_info['deleted'],
@@ -111,6 +134,12 @@ class file_check extends task_base
 					return file_exists($root_path . $filename);
 				}
 			);
+
+			// Remove files to delete list if empty
+			if (count($file_update_info['delete']) < 1)
+			{
+				unset($file_update_info['delete']);
+			}
 		}
 
 		$progress_count = $this->installer_config->get('file_check_progress_count', 0);
diff --git a/phpBB/phpbb/install/module/update_filesystem/task/show_file_status.php b/phpBB/phpbb/install/module/update_filesystem/task/show_file_status.php
index cf1e4cf4ac..0e82f91553 100644
--- a/phpBB/phpbb/install/module/update_filesystem/task/show_file_status.php
+++ b/phpBB/phpbb/install/module/update_filesystem/task/show_file_status.php
@@ -129,9 +129,9 @@ class show_file_status extends task_base
 
 			// Add form to continue update
 			$this->iohandler->add_user_form_group('UPDATE_CONTINUE_FILE_UPDATE', array(
-				'submit_continue_file_update'	=> array(
-					'label'	=> 'UPDATE_CONTINUE_FILE_UPDATE',
-					'type'	=> 'submit',
+				'submit_continue_file_update' => array(
+					'label' => 'UPDATE_CONTINUE_FILE_UPDATE',
+					'type' => 'submit',
 				),
 			));