diff --git a/phpBB/adm/style/install_update.html b/phpBB/adm/style/install_update.html
index 6b361ec3f1..c9a8e4e6c1 100644
--- a/phpBB/adm/style/install_update.html
+++ b/phpBB/adm/style/install_update.html
@@ -185,10 +185,34 @@
 								<br /><span>{L_NUM_CONFLICTS}: {files.NUM_CONFLICTS}</span>
 								<!-- ENDIF -->
 							</dt>
-							<dd style="margin-left: 60%;"><!-- IF not files.S_BINARY -->[ <a href="{files.U_SHOW_DIFF}" onclick="popup('{files.U_SHOW_DIFF}', 700, 500); return false;">{files.L_SHOW_DIFF}</a> ]<!-- ELSE -->{L_BINARY_FILE}<!-- ENDIF --></dd>
+							<dd style="margin-left: 60%;"><!-- IF files.STATUS eq 'modified' -->&nbsp;<!-- ELSE --><!-- IF not files.S_BINARY -->[ <a href="{files.U_SHOW_DIFF}" onclick="popup('{files.U_SHOW_DIFF}', 700, 500); return false;">{files.L_SHOW_DIFF}</a> ]<!-- ELSE -->{L_BINARY_FILE}<!-- ENDIF --><!-- ENDIF --></dd>
 							<!-- IF files.S_CUSTOM -->
 								<dd style="margin-left: 60%;"><label><input type="checkbox" name="no_update[]" value="{files.FILENAME}" class="radio" /> {L_DO_NOT_UPDATE}</label></dd>
 							<!-- ENDIF -->
+							
+							<!-- IF files.STATUS eq 'modified' -->
+							</dl>
+							<dl>
+								<dt style="width: 60%"><label><input type="radio" class="radio" name="modified[{files.FILENAME}]" value="0" checked="checked" /> {L_MERGE_MODIFICATIONS_OPTION}</label></dt>
+								<dd style="margin-left: 60%;"><!-- IF not files.S_BINARY -->[ <a href="{files.U_SHOW_DIFF}" onclick="popup('{files.U_SHOW_DIFF}', 700, 500); return false;">{files.L_SHOW_DIFF}</a> ]<!-- ELSE -->{L_BINARY_FILE}<!-- ENDIF --></dd>
+							</dl>
+							<dl>
+								<dt style="width: 60%"><label><input type="radio" class="radio" name="modified[{files.FILENAME}]" value="1" /> {L_MERGE_NO_MERGE_NEW_OPTION}</label></dt>
+								<dd style="margin-left: 60%;"><!-- IF not files.S_BINARY -->[<a href="{files.U_VIEW_NO_MERGE_NEW}" onclick="popup('{files.U_VIEW_NO_MERGE_NEW}', 700, 500); return false;">{L_SHOW_DIFF_FINAL}</a>]<!-- ELSE -->&nbsp;<!-- ENDIF --></dd>
+							</dl>
+							<dl>
+								<dt style="width: 60%"><label><input type="radio" class="radio" name="modified[{files.FILENAME}]" value="2" /> {L_MERGE_NO_MERGE_MOD_OPTION}</label></dt>
+								<dd style="margin-left: 60%;"><!-- IF not files.S_BINARY -->[<a href="{files.U_VIEW_NO_MERGE_MOD}" onclick="popup('{files.U_VIEW_NO_MERGE_MOD}', 700, 500); return false;">{L_SHOW_DIFF_FINAL}</a>]<!-- ELSE -->&nbsp;<!-- ENDIF --></dd>
+							</dl>
+							<!-- IF not files.S_LAST_ROW -->
+							</fieldset>
+
+							<fieldset>
+								<legend><img src="{T_IMAGE_PATH}file_{files.STATUS}.gif" alt="{files.L_STATUS}" /></legend>
+							<!-- ENDIF -->
+
+							<!-- ENDIF -->
+
 							<!-- IF files.STATUS eq 'conflict' -->
 							</dl>
 							<dl>
@@ -218,7 +242,7 @@
 
 							<!-- ENDIF -->
 						<!-- ENDIF -->
-					<!-- IF files.STATUS neq 'conflict' --></dl><!-- ENDIF -->
+					<!-- IF files.STATUS neq 'conflict' and files.STATUS neq 'modified' --></dl><!-- ENDIF -->
 				<!-- ENDIF -->
 			<!-- END files -->
 
diff --git a/phpBB/adm/style/install_update_diff.html b/phpBB/adm/style/install_update_diff.html
index 54242d94b4..799ca34292 100644
--- a/phpBB/adm/style/install_update_diff.html
+++ b/phpBB/adm/style/install_update_diff.html
@@ -42,11 +42,16 @@ function resize_panel()
 	width: 99%;
 }
 
+#diff_content {
+	padding: 30px 10px 10px;
+}
+
 <!-- IF DIFF_MODE neq 'side_by_side' and DIFF_MODE neq 'raw' -->
 div#codepanel {
 	overflow: auto;
 	width: 100%;
 	height: 350px;
+	display: inline-block;
 }
 <!-- ELSE -->
 div#codepanel {	
@@ -230,7 +235,7 @@ table.hrdiff caption span {
 		<div id="acp">
 		<div class="panel" id="codepanel">
 			<span class="corners-top"><span></span></span>
-				<div id="content">
+				<div id="diff_content">
 					<div id="main">
 
 <!-- IF S_DIFF_CONFLICT_FILE -->
diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index bb1ace4c49..1b4cbf8f91 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -188,6 +188,7 @@ p a {
 	<ul class="menu">
 		<li>[Fix] Parse error in MCP ban (Bug #13109)</li>
 		<li>[Fix] Correctly hide online status in the profile (Bug #13059)</li>
+		<li>[Feature] Let the user choose how to update modified files (merging, using new file or using old file) within automatic updater</li>
 
 	</ul>
 
@@ -209,7 +210,7 @@ p a {
 		<li>[Fix] Correct approval of posts in global announcements (Bug #12699)</li>
 		<li>[Sec] Do not allow setup spiders/robots to post, even if permissions are given. We see no reason why this should be possible. (Thanks to Frank Rizzo for convincing us regarding this)</li>
 		<li>[Sec] Do not display the last active column within the memberlist if u_viewonline permission is not given (Bug #12797)</li>
-		<li>[Fix] Display custom profile field &quotdate&quot; based on users language (Bug #12787)</li>
+		<li>[Fix] Display custom profile field &quot;date&quot; based on users language (Bug #12787)</li>
 		<li>[Fix] Allow adding of help language files within subdirectories (Bug #12783)</li>
 		<li>[Fix] Correctly apply smileys on posting having # within their emotion code</li>
 		<li>[Fix] Correctly convert smileys having double quotes within their emotion code (Bug #12731)</li>
diff --git a/phpBB/includes/functions_module.php b/phpBB/includes/functions_module.php
index 1010de643b..073dfa60ad 100644
--- a/phpBB/includes/functions_module.php
+++ b/phpBB/includes/functions_module.php
@@ -127,10 +127,14 @@ class p_master
 		if (file_exists($user->lang_path . 'mods'))
 		{
 			$add_files = array();
+			$info_files = glob($user->lang_path . 'mods/info_' . strtolower($this->p_class) . '_*.' . $phpEx, GLOB_NOSORT);
 
-			foreach (glob($user->lang_path . 'mods/info_' . strtolower($this->p_class) . '_*.' . $phpEx, GLOB_NOSORT) as $file)
+			if ($info_files !== false && sizeof($info_files))
 			{
-				$add_files[] = 'mods/' . substr(basename($file), 0, -(strlen($phpEx) + 1));
+				foreach ($info_files as $file)
+				{
+					$add_files[] = 'mods/' . substr(basename($file), 0, -(strlen($phpEx) + 1));
+				}
 			}
 
 			if (sizeof($add_files))
diff --git a/phpBB/install/install_update.php b/phpBB/install/install_update.php
index bf1912076f..3a7cbaf37b 100644
--- a/phpBB/install/install_update.php
+++ b/phpBB/install/install_update.php
@@ -82,7 +82,7 @@ class install_update extends module
 		require($phpbb_root_path . 'includes/db/' . $dbms . '.' . $phpEx);
 		require($phpbb_root_path . 'includes/constants.' . $phpEx);
 
-		// Special options for conflicts
+		// Special options for conflicts/modified files
 		define('MERGE_NO_MERGE_NEW', 1);
 		define('MERGE_NO_MERGE_MOD', 2);
 		define('MERGE_NEW_FILE', 3);
@@ -476,11 +476,23 @@ class install_update extends module
 				$this->page_title = 'STAGE_UPDATE_FILES';
 
 				$s_hidden_fields = '';
-				foreach (request_var('conflict', array('' => 0)) as $filename => $merge_option)
+				$conflicts = request_var('conflict', array('' => 0));
+				$modified = request_var('modified', array('' => 0));
+
+				foreach ($conflicts as $filename => $merge_option)
 				{
 					$s_hidden_fields .= '<input type="hidden" name="conflict[' . htmlspecialchars($filename) . ']" value="' . $merge_option . '" />';
 				}
 
+				foreach ($modified as $filename => $merge_option)
+				{
+					if (!$merge_option)
+					{
+						continue;
+					}
+					$s_hidden_fields .= '<input type="hidden" name="modified[' . htmlspecialchars($filename) . ']" value="' . $merge_option . '" />';
+				}
+
 				$no_update = request_var('no_update', array(0 => ''));
 
 				foreach ($no_update as $index => $filename)
@@ -645,6 +657,7 @@ class install_update extends module
 
 				$update_list = $cache->get('_update_list');
 				$conflicts = request_var('conflict', array('' => 0));
+				$modified = request_var('modified', array('' => 0));
 
 				if ($update_list === false)
 				{
@@ -672,6 +685,28 @@ class install_update extends module
 					$conflicts = $new_conflicts;
 				}
 
+				// Build list for modifications
+				if (sizeof($modified))
+				{
+					$modified_filenames = array();
+					foreach ($update_list['modified'] as $files)
+					{
+						$modified_filenames[] = $files['filename'];
+					}
+
+					$new_modified = array();
+					foreach ($modified as $filename => $diff_method)
+					{
+						if (in_array($filename, $modified_filenames))
+						{
+							$new_modified[$filename] = $diff_method;
+						}
+					}
+
+					$modified = $new_modified;
+				}
+
+				// Check number of conflicting files, they need to be equal. For modified files the number can differ
 				if (sizeof($update_list['conflict']) != sizeof($conflicts))
 				{
 					trigger_error($user->lang['MERGE_SELECT_ERROR'], E_USER_ERROR);
@@ -729,10 +764,25 @@ class install_update extends module
 
 							case 'modified':
 
-								$diff = $this->return_diff($this->old_location . $original_filename, $phpbb_root_path . $file_struct['filename'], $this->new_location . $original_filename);
+								$option = (isset($modified[$file_struct['filename']])) ? $modified[$file_struct['filename']] : 0;
 
-								$contents = implode("\n", $diff->merged_output());
-								unset($diff);
+								switch ($option)
+								{
+									case MERGE_NO_MERGE_NEW:
+										$contents = file_get_contents($this->new_location . $original_filename);
+									break;
+
+									case MERGE_NO_MERGE_MOD:
+										$contents = file_get_contents($phpbb_root_path . $file_struct['filename']);
+									break;
+
+									default:
+										$diff = $this->return_diff($this->old_location . $original_filename, $phpbb_root_path . $file_struct['filename'], $this->new_location . $original_filename);
+
+										$contents = implode("\n", $diff->merged_output());
+										unset($diff);
+									break;
+								}
 
 								if ($update_mode == 'download')
 								{
@@ -921,7 +971,25 @@ class install_update extends module
 			break;
 
 			case 'modified':
-				$diff = $this->return_diff($this->old_location . $original_file, $phpbb_root_path . $original_file, $this->new_location . $file);
+				$option = request_var('op', 0);
+
+				switch ($option)
+				{
+					case MERGE_NO_MERGE_NEW:
+					case MERGE_NO_MERGE_MOD:
+
+						$diff = $this->return_diff(array(), ($option == MERGE_NO_MERGE_NEW) ? $this->new_location . $original_file : $phpbb_root_path . $file);
+
+						$template->assign_var('S_DIFF_NEW_FILE', true);
+						$diff_mode = 'inline';
+						$this->page_title = 'VIEWING_FILE_CONTENTS';
+
+					break;
+
+					default:
+						$diff = $this->return_diff($this->old_location . $original_file, $phpbb_root_path . $original_file, $this->new_location . $file);
+					break;
+				}
 			break;
 
 			case 'not_modified':
diff --git a/phpBB/language/en/install.php b/phpBB/language/en/install.php
index 180157d5e0..8fd95bc0ae 100755
--- a/phpBB/language/en/install.php
+++ b/phpBB/language/en/install.php
@@ -421,6 +421,9 @@ $lang = array_merge($lang, array(
 	'LOGIN_UPDATE_EXPLAIN'	=> 'In order to update your installation you need to login first.',
 
 	'MAPPING_FILE_STRUCTURE'	=> 'To ease the upload here are the file locations which map your phpBB installation.',
+
+	'MERGE_MODIFICATIONS_OPTION'	=> 'Merge modifications',
+
 	'MERGE_NO_MERGE_NEW_OPTION'	=> 'Do not merge - use new file',
 	'MERGE_NO_MERGE_MOD_OPTION'	=> 'Do not merge - use currently installed file',
 	'MERGE_MOD_FILE_OPTION'		=> 'Merge differences and use modified code within conflicting block',