fixes #1040 move check upgrade action to maintenance page

admin/maintenance.php

@@ -186,6 +186,58 @@ DELETE
     clear_derivative_cache($_GET['type']);
     break;
   }
+
+  case 'check_upgrade':
+  {
+    if (!fetchRemote(PHPWG_URL.'/download/latest_version', $result))
+    {
+      $page['errors'][] = l10n('Unable to check for upgrade.');
+    }
+    else
+    {
+      $versions = array('current' => PHPWG_VERSION);
+      $lines = @explode("\r\n", $result);
+  
+      // if the current version is a BSF (development branch) build, we check
+      // the first line, for stable versions, we check the second line
+      if (preg_match('/^BSF/', $versions['current']))
+      {
+        $versions['latest'] = trim($lines[0]);
+  
+        // because integer are limited to 4,294,967,296 we need to split BSF
+        // versions in date.time
+        foreach ($versions as $key => $value)
+        {
+          $versions[$key] =
+            preg_replace('/BSF_(\d{8})(\d{4})/', '$1.$2', $value);
+        }
+      }
+      else
+      {
+        $versions['latest'] = trim($lines[1]);
+      }
+  
+      if ('' == $versions['latest'])
+      {
+        $page['errors'][] = l10n('Check for upgrade failed for unknown reasons.');
+      }
+      // concatenation needed to avoid automatic transformation by release
+      // script generator
+      else if ('%'.'PWGVERSION'.'%' == $versions['current'])
+      {
+        $page['infos'][] = l10n('You are running on development sources, no check possible.');
+      }
+      else if (version_compare($versions['current'], $versions['latest']) < 0)
+      {
+        $page['infos'][] = l10n('A new version of Piwigo is available.');
+      }
+      else
+      {
+        $page['infos'][] = l10n('You are running the latest version of Piwigo.');
+      }
+    }
+  }
+
   default :
   {
     break;
@@ -232,6 +284,7 @@ $template->assign(
 
     'PHPWG_URL' => PHPWG_URL,
     'PWG_VERSION' => PHPWG_VERSION,
+    'U_CHECK_UPGRADE' => sprintf($url_format, 'check_upgrade'),
     'OS' => PHP_OS,
     'PHP_VERSION' => phpversion(),
     'DB_ENGINE' => 'MySQL',