diff --git a/Makefile b/Makefile
index b53a1c6e0d..a040894b5b 100644
--- a/Makefile
+++ b/Makefile
@@ -66,6 +66,7 @@ zentaoxx:
 	cp -r xuan/xxb/module/client zentaoxx/module/
 	cp -r xuan/xxb/module/license zentaoxx/module/
 	cp -r xuan/xxb/module/owt zentaoxx/module/
+	cp xuan/xxb/apischeme.json zentaoxx/
 	mkdir -p zentaoxx/module/common/view
 	cp -r xuan/xxb/module/common/view/header.modal.html.php zentaoxx/module/common/view
 	cp -r xuan/xxb/module/common/view/marked.html.php zentaoxx/module/common/view
diff --git a/framework/base/router.class.php b/framework/base/router.class.php
index ed768a633a..10604d95a2 100644
--- a/framework/base/router.class.php
+++ b/framework/base/router.class.php
@@ -1378,7 +1378,7 @@ class baseRouter
         if(empty($extFiles) and empty($hookFiles)) return $mainModelFile;
 
         /* 计算合并之后的modelFile路径。Compute the merged model file path. */
-        $extModelPrefix  = ($siteExtended and !empty($this->siteCode)) ? $this->siteCode{0} . DS . $this->siteCode : '';
+        $extModelPrefix  = ($siteExtended and !empty($this->siteCode)) ? $this->siteCode[0] . DS . $this->siteCode : '';
         $mergedModelDir  = $this->getTmpRoot() . 'model' . DS . ($extModelPrefix ? $extModelPrefix . DS : '');
         $mergedModelFile = $mergedModelDir . $moduleName . '.php';
         if(!is_dir($mergedModelDir)) mkdir($mergedModelDir, 0755, true);
diff --git a/lib/purifier/HTMLPurifier/ChildDef/Custom.php b/lib/purifier/HTMLPurifier/ChildDef/Custom.php
index 1047cd8e8b..cc84d89908 100644
--- a/lib/purifier/HTMLPurifier/ChildDef/Custom.php
+++ b/lib/purifier/HTMLPurifier/ChildDef/Custom.php
@@ -45,7 +45,7 @@ class HTMLPurifier_ChildDef_Custom extends HTMLPurifier_ChildDef
     protected function _compileRegex()
     {
         $raw = str_replace(' ', '', $this->dtd_regex);
-        if ($raw{0} != '(') {
+        if ($raw[0] != '(') {
             $raw = "($raw)";
         }
         $el = '[#a-zA-Z0-9_.-]+';
diff --git a/lib/purifier/HTMLPurifier/TagTransform/Font.php b/lib/purifier/HTMLPurifier/TagTransform/Font.php
index 2a186515e2..99e01658cc 100644
--- a/lib/purifier/HTMLPurifier/TagTransform/Font.php
+++ b/lib/purifier/HTMLPurifier/TagTransform/Font.php
@@ -75,7 +75,7 @@ class HTMLPurifier_TagTransform_Font extends HTMLPurifier_TagTransform
         if (isset($attr['size'])) {
             // normalize large numbers
             if ($attr['size'] !== '') {
-                if ($attr['size']{0} == '+' || $attr['size']{0} == '-') {
+                if ($attr['size'][0] == '+' || $attr['size'][0] == '-') {
                     $size = (int)$attr['size'];
                     if ($size < -2) {
                         $attr['size'] = '-2';
diff --git a/lib/scm/gitrepo.class.php b/lib/scm/gitrepo.class.php
index 2478569f16..304c9dbce3 100644
--- a/lib/scm/gitrepo.class.php
+++ b/lib/scm/gitrepo.class.php
@@ -124,7 +124,7 @@ class GitRepo
         $branches = array();
         foreach($list as $localBranch)
         {
-            if($localBranch{0} == '*') $localBranch = substr($localBranch, 1);
+            if($localBranch[0] == '*') $localBranch = substr($localBranch, 1);
 
             $localBranch = trim($localBranch);
             if(empty($localBranch))continue;
@@ -216,7 +216,7 @@ class GitRepo
         foreach($list as $line)
         {
             if(empty($line)) continue;
-            if($line{0} == '^') $line = substr($line, 1);
+            if($line[0] == '^') $line = substr($line, 1);
             preg_match('/^([0-9a-f]{39,40})\s.*\((\S+)\s+([\d-]+)\s(.*)\s(\d+)\)(.*)$/U', $line, $matches);
 
             if(isset($matches[1]) and $matches[1] != $revision)
@@ -385,7 +385,7 @@ class GitRepo
 
                             $line = $lines[$i];
                             if(strpos($line, '\ No newline at end of file') === 0)continue;
-                            $sign = empty($line) ? '' : $line{0};
+                            $sign = empty($line) ? '' : $line[0];
                             if($sign == '-' and $newFile) $sign = '+';
                             $type = $sign != '-' ? $sign == '+' ? 'new' : 'all' : 'old';
                             if($sign == '-' || $sign == '+')
diff --git a/lib/scm/subversion.class.php b/lib/scm/subversion.class.php
index 02e80e8efa..5eb5b3a63f 100644
--- a/lib/scm/subversion.class.php
+++ b/lib/scm/subversion.class.php
@@ -447,7 +447,7 @@ class Subversion
 
                             $line = $lines[$i];
                             if(strpos($line, '\ No newline at end of file') === 0)continue;
-                            $sign = empty($line) ? '' : $line{0};
+                            $sign = empty($line) ? '' : $line[0];
                             $type = $sign != '-' ? $sign == '+' ? 'new' : 'all' : 'old';
                             if($sign == '-' || $sign == '+') $line = substr_replace($line, ' ', 1, 0);
 
diff --git a/lib/zdb/zdb.class.php b/lib/zdb/zdb.class.php
index d70f4526f9..1a5cceca37 100644
--- a/lib/zdb/zdb.class.php
+++ b/lib/zdb/zdb.class.php
@@ -12,16 +12,16 @@
 class zdb
 {
     /**
-     * dbh 
-     * 
-     * @var object   
+     * dbh
+     *
+     * @var object
      * @access public
      */
     public $dbh;
 
     /**
-     * Construct 
-     * 
+     * Construct
+     *
      * @access public
      * @return void
      */
@@ -33,33 +33,159 @@ class zdb
 
     /**
      * Get all tables.
-     * 
+     *
+     * @param  string $type  if type is 'base', just get base table.
      * @access public
      * @return array
      */
-    public function getAllTables()
+    public function getAllTables($type = 'base')
     {
         global $config;
 
         $allTables = array();
         $stmt      = $this->dbh->query("show full tables");
-        while($table = $stmt->fetch(PDO::FETCH_ASSOC)) 
+        while($table = $stmt->fetch(PDO::FETCH_ASSOC))
         {
             $tableType = strtolower($table['Table_type']);
-            if($tableType != 'base table') continue;
+            if($type == 'base' and $tableType != 'base table') continue;
 
             $tableName = $table["Tables_in_{$config->db->name}"];
-            $allTables[$tableName] = 'table';
+            $allTables[$tableName] = $tableType == 'base table' ? 'table' : $tableType;
         }
 
         return $allTables;
     }
 
     /**
-     * Dump db. 
-     * 
-     * @param  string $fileName 
-     * @param  array  $tables 
+     * Get table fields.
+     *
+     * @param  string $table
+     * @access public
+     * @return array
+     */
+    public function getTableFields($table)
+    {
+        try
+        {
+            $this->dbh->setAttribute(PDO::ATTR_CASE, PDO::CASE_LOWER);
+            $sql = "DESC $table";
+            $rawFields = $this->dbh->query($sql)->fetchAll();
+            $this->dbh->setAttribute(PDO::ATTR_CASE, PDO::CASE_NATURAL);
+        }
+        catch (PDOException $e)
+        {
+            global $dao;
+            $dao->sqlError($e);
+        }
+
+        $fields = array();
+        foreach($rawFields as $field) $fields[$field->field] = $field;
+
+        return $fields;
+    }
+
+    /**
+     * Diff current table fields with a fields array.
+     *
+     * @param  string $table
+     * @param  array  $fields
+     * @access public
+     * @return array
+     */
+    public function diffTable($table, $fields)
+    {
+        $tableFields = $this->getTableFields($table);
+
+        $diff = array_udiff_assoc($fields, $tableFields,
+            function($a, $b)
+            {
+                return (array)$a == (array)$b ? 0 : 1;
+            }
+        );
+
+        return $diff;
+    }
+
+    /**
+     * Add a column to a table, or modify a existing column.
+     *
+     * @param  string  $table
+     * @param  object  $column
+     * @param  boolean $add    if true, add $column as a new column, otherwise modify a existing column to $column.
+     * @access public
+     * @return object
+     */
+    public function updateColumn($table, $column, $add = true)
+    {
+        $return = new stdclass();
+        $return->result = true;
+        $return->error  = '';
+
+        $query = "ALTER TABLE `$table` " . ($add ? 'ADD' : 'MODIFY COLUMN') . " `$column->field` $column->type" . ($column->null == 'NO' ? ' NOT NULL' : '') . (is_null($column->default) ? '' : " DEFAULT '$column->default'") . (empty($column->extra) ? '' : " $column->extra") . ';';
+
+        try
+        {
+            $this->dbh->exec($query);
+            return $return;
+        }
+        catch(PDOException $e)
+        {
+            $return->result = false;
+            $return->error  = $e->getMessage();
+            $return->sql    = $query;
+            return $return;
+        }
+    }
+
+    /**
+     * Create a table with fields.
+     *
+     * @param  string $name
+     * @param  array  $fields
+     * @access public
+     * @return object
+     */
+    public function createTable($name, $fields)
+    {
+        $return = new stdclass();
+        $return->result = true;
+        $return->error  = '';
+        $createTableQuery = "CREATE TABLE `$name` (";
+
+        foreach($fields as $field)
+        {
+            $createColumnQuery = "`$field->field` $field->type" . ($field->null == 'NO' ? ' NOT NULL' : '') . (is_null($field->default) ? '' : " DEFAULT '$field->default'") . (empty($field->extra) ? '' : " $field->extra") . ", ";
+            if(!empty($field->key))
+            {
+                if($field->key === 'PRI') $createColumnQuery .= "PRIMARY KEY (`{$field->field}`), ";
+                if($field->key === 'MUL') $createColumnQuery .= "KEY `{$field->field}` (`{$field->field}`), ";
+                if($field->key === 'UNI') $createColumnQuery .= "UNIQUE KEY `{$field->field}` (`{$field->field}`), ";
+            }
+            $createTableQuery .= $createColumnQuery;
+        }
+
+        $createTableQuery = rtrim($createTableQuery, ', ');
+        $createTableQuery .= ") ENGINE=MyISAM DEFAULT CHARSET=utf8;";
+
+        try
+        {
+            $this->dbh->exec($createTableQuery);
+            return $return;
+        }
+        catch(PDOException $e)
+        {
+            $return->result = false;
+            $return->error  = $e->getMessage();
+            $return->sql    = $createTableQuery;
+            return $return;
+        }
+    }
+
+    /**
+     * Dump db.
+     *
+     * @param  string $fileName
+     * @param  array  $tables
      * @access public
      * @return object
      */
@@ -139,10 +265,11 @@ class zdb
     }
 
     /**
-     * Import DB 
-     * 
+     * Import DB
+     *
+     * @param  string $fileName
      * @access public
-     * @return object;
+     * @return object
      */
     public function import($fileName)
     {
@@ -210,10 +337,10 @@ class zdb
 
     /**
      * Get schema SQL.
-     * 
-     * @param  string    $table 
+     *
+     * @param  string $table
      * @access public
-     * @return string
+     * @return object
      */
     public function getSchemaSQL($table, $type = 'table')
     {
diff --git a/module/common/model.php b/module/common/model.php
index 81d73d047f..d7e3093493 100644
--- a/module/common/model.php
+++ b/module/common/model.php
@@ -254,7 +254,7 @@ class commonModel extends model
             {
                 echo '<li class="user-profile-item">';
                 echo "<a href='" . helper::createLink('my', 'profile') . "' class='" . (!empty($app->user->role) && isset($lang->user->roleList[$app->user->role]) ? '' : ' no-role') . "'>";
-                echo "<div class='avatar avatar bg-secondary avatar-circle'>" . strtoupper($app->user->account{0}) . "</div>\n";
+                echo "<div class='avatar avatar bg-secondary avatar-circle'>" . strtoupper($app->user->account[0]) . "</div>\n";
                 echo '<div class="user-profile-name">' . (empty($app->user->realname) ? $app->user->account : $app->user->realname) . '</div>';
                 if(isset($lang->user->roleList[$app->user->role])) echo '<div class="user-profile-role">' . $lang->user->roleList[$app->user->role] . '</div>';
                 echo '</a></li><li class="divider"></li>';
@@ -1766,7 +1766,7 @@ EOD;
         {
             $timestamp = $queryString['time'];
             if(strlen($timestamp) > 10) $timestamp = substr($timestamp, 0, 10);
-            if(strlen($timestamp) != 10 or $timestamp{0} >= '4') $this->response('ERROR_TIMESTAMP');
+            if(strlen($timestamp) != 10 or $timestamp[0] >= '4') $this->response('ERROR_TIMESTAMP');
 
             $result = $this->get->token == md5($entry->code . $entry->key . $queryString['time']);
             if($result)
diff --git a/module/common/view/footer.html.php b/module/common/view/footer.html.php
index 68cec35337..79f40320d2 100755
--- a/module/common/view/footer.html.php
+++ b/module/common/view/footer.html.php
@@ -22,7 +22,7 @@ $.initSidebar();
 <div id="noticeBox"><?php echo $this->loadModel('score')->getNotice(); ?></div>
 <script>
 <?php if(!isset($config->global->browserNotice)):?>
-browserNotice = <?php echo helper::jsonEncode($lang->browserNotice)?>;
+browserNotice = <?php echo json_encode($lang->browserNotice)?>;
 function ajaxIgnoreBrowser(){$.get(createLink('misc', 'ajaxIgnoreBrowser'));}
 $(function(){showBrowserNotice()});
 <?php endif;?>
diff --git a/module/file/model.php b/module/file/model.php
index 1fe052d4e8..ad1f9e8f23 100644
--- a/module/file/model.php
+++ b/module/file/model.php
@@ -569,7 +569,7 @@ class fileModel extends model
                 while($line)
                 {
                     /* the cell has '"', the delimiter is '",'. */
-                    if($line{0} == '"')
+                    if($line[0] == '"')
                     {
                         $pos  = strpos($line, '",');
                         if($pos === false)
diff --git a/module/git/model.php b/module/git/model.php
index 8159a23d28..4859b96eb8 100644
--- a/module/git/model.php
+++ b/module/git/model.php
@@ -361,7 +361,7 @@ class gitModel extends model
         chdir($repo->path);
         exec("{$this->client} config core.quotepath false");
         $subPath = substr($path, strlen($repo->path));
-        if($subPath{0} == '/' or $subPath{0} == '\\') $subPath = substr($subPath, 1);
+        if($subPath[0] == '/' or $subPath[0] == '\\') $subPath = substr($subPath, 1);
 
         $encodings = explode(',', $this->config->git->encodings);
         foreach($encodings as $encoding)
@@ -402,7 +402,7 @@ class gitModel extends model
         putenv('LC_CTYPE=en_US.UTF-8');
 
         $subPath = substr($path, strlen($repo->path));
-        if($subPath{0} == '/' or $subPath{0} == '\\') $subPath = substr($subPath, 1);
+        if($subPath[0] == '/' or $subPath[0] == '\\') $subPath = substr($subPath, 1);
 
         $encodings = explode(',', $this->config->git->encodings);
         foreach($encodings as $encoding)
diff --git a/module/task/model.php b/module/task/model.php
index 9f541081f2..5e35d8e9b1 100644
--- a/module/task/model.php
+++ b/module/task/model.php
@@ -579,6 +579,7 @@ class taskModel extends model
             $currentTask = !empty($task) ? $task : new stdclass();
             if(!isset($currentTask->status)) $currentTask->status = $oldTask->status;
 
+            $currentTask->assignedTo = $oldTask->assignedTo;
             if(!empty($this->post->assignedTo))
             {
                 $currentTask->assignedTo = $this->post->assignedTo;
@@ -1155,8 +1156,8 @@ class taskModel extends model
         $estimate = new stdclass();
         $estimate->date     = zget($task, 'realStarted', date(DT_DATE1));
         $estimate->task     = $taskID;
-        $estimate->consumed = zget($task, 'consumed', 0);
-        $estimate->left     = zget($task, 'left', 0);
+        $estimate->consumed = zget($_POST, 'consumed', 0);
+        $estimate->left     = zget($_POST, 'left', 0);
         $estimate->work     = zget($task, 'work', '');
         $estimate->account  = $this->app->user->account;
         $estimate->consumed = $estimate->consumed - $oldTask->consumed;
@@ -1378,14 +1379,20 @@ class taskModel extends model
         }
 
         $estimate = new stdclass();
-        $estimate->date     = zget($task, 'finishedDate', date(DT_DATE1));
+        $estimate->date     = zget($_POST, 'finishedDate', date(DT_DATE1));
         $estimate->task     = $taskID;
-        $estimate->consumed = zget($task, 'consumed', 0);
-        $estimate->left     = zget($task, 'left', 0);
+        $estimate->left     = 0;
         $estimate->work     = zget($task, 'work', '');
         $estimate->account  = $this->app->user->account;
-
         $estimate->consumed = $consumed;
+        if(!empty($oldTask->team))
+        {
+            foreach($oldTask->team as $teamAccount => $team)
+            {
+                if($teamAccount == $this->app->user->account) continue;
+                $estimate->left += $team->left;
+            }
+        }
         if($estimate->consumed) $this->addTaskEstimate($estimate);
 
         if(!empty($oldTask->team))
diff --git a/module/tree/model.php b/module/tree/model.php
index 902c961e3d..fb2d56ec45 100644
--- a/module/tree/model.php
+++ b/module/tree/model.php
@@ -1668,7 +1668,7 @@ class treeModel extends model
             $createdVersion = $this->dao->select($versionField)->from($table)->where('id')->eq($rootID)->fetch($versionField);
             if($createdVersion)
             {
-                if(is_numeric($createdVersion{0}) and version_compare($createdVersion, '4.1', '<=')) return false;
+                if(is_numeric($createdVersion[0]) and version_compare($createdVersion, '4.1', '<=')) return false;
                 return true;
             }
         }
diff --git a/www/index.php b/www/index.php
index 2cd1afad13..4b751cb20d 100644
--- a/www/index.php
+++ b/www/index.php
@@ -43,7 +43,7 @@ if(isset($_GET['mode']) and $_GET['mode'] == 'getconfig') die(helper::removeUTF8
 
 /* Check for need upgrade. */
 $config->installedVersion = $common->loadModel('setting')->getVersion();
-if(((is_numeric($config->version{0}) and is_numeric($config->installedVersion{0})) or $config->version{0} == $config->installedVersion{0}) and version_compare($config->version, $config->installedVersion, '>')) die(header('location: upgrade.php'));
+if(((is_numeric($config->version[0]) and is_numeric($config->installedVersion[0])) or $config->version[0] == $config->installedVersion[0]) and version_compare($config->version, $config->installedVersion, '>')) die(header('location: upgrade.php'));
 
 /* Remove install.php and upgrade.php. */
 if(file_exists('install.php') or file_exists('upgrade.php'))
diff --git a/www/upgrade.php.tmp b/www/upgrade.php.tmp
index 13abaab89e..2856517a7e 100644
--- a/www/upgrade.php.tmp
+++ b/www/upgrade.php.tmp
@@ -56,7 +56,7 @@ $app->setDebug();
 
 /* Check the installed version is the latest or not. */
 $config->installedVersion = $common->loadModel('setting')->getVersion();
-if(($config->version{0} == $config->installedVersion{0} or (is_numeric($config->version{0}) and is_numeric($config->installedVersion{0}))) and version_compare($config->version, $config->installedVersion) <= 0) die(header('location: index.php'));
+if(($config->version[0] == $config->installedVersion[0] or (is_numeric($config->version[0]) and is_numeric($config->installedVersion[0]))) and version_compare($config->version, $config->installedVersion) <= 0) die(header('location: index.php'));
 
 /* Run it. */
 $app->parseRequest();
diff --git a/xuanxuan/module/message/ext/model/class/xuanxuan.class.php b/xuanxuan/module/message/ext/model/class/xuanxuan.class.php
index 723117c375..812c3366e6 100644
--- a/xuanxuan/module/message/ext/model/class/xuanxuan.class.php
+++ b/xuanxuan/module/message/ext/model/class/xuanxuan.class.php
@@ -19,7 +19,7 @@ class xuanxuanMessage extends messageModel
                 $server   = $this->loadModel('im')->getServer('zentao');
                 $onlybody = isset($_GET['onlybody']) ? $_GET['onlybody'] : '';
                 unset($_GET['onlybody']);
-                $url = $server . helper::createLink($objectType, 'view', "id=$objectID", 'xhtml');
+                $url = $server . helper::createLink($objectType, 'view', "id=$objectID", 'html');
                 $url = "xxc:openInApp/zentao-integrated/" . urlencode($url);
 
                 $target = '';