- #27231: Friendly DB error screens.

includes/bootstrap.inc

@@ -864,4 +864,20 @@ function _drupal_bootstrap($phase) {
   }
 }
 
+/**
+ * Enables use of the theme system without requiring database access. Since
+ * there is not database access no theme will be enabled and the default
+ * themable fuctions will be called. Some themable functions can not be used
+ * without the full Drupal API loaded. For example, theme_page() is
+ * unavailable and theme_maintenance_page() must be used in its place.
+ */
+function drupal_maintenance_theme() {
+  global $theme;
+  require_once './includes/theme.inc';
+  require_once './includes/common.inc';
+  require_once './includes/unicode.inc';
+  unicode_check();
+  $theme = '';
+}
+
 ?>

includes/common.inc

@@ -1831,7 +1831,7 @@ function drupal_implode_autocomplete($array) {
 
 function _drupal_bootstrap_full() {
   static $called;
-  global $locale, $multibyte;
+  global $locale;
 
   if ($called) {
     return;
@@ -1850,7 +1850,7 @@ function _drupal_bootstrap_full() {
   // Emit the correct charset HTTP header.
   drupal_set_header('Content-Type: text/html; charset=utf-8');
   // Detect string handling method
-  $multibyte = unicode_check();
+  unicode_check();
   // Initialize $_GET['q'] prior to loading modules and invoking hook_init().
   if (!empty($_GET['q'])) {
     $_GET['q'] = drupal_get_normal_path(trim($_GET['q'], '/'));

includes/database.inc

@@ -116,7 +116,11 @@ function db_set_active($name = 'default') {
       include_once($handler);
     }
     else {
-      die('Unsupported database type');
+      drupal_maintenance_theme();
+      drupal_set_title('Unsupported database type');
+      print theme('maintenance_page', '<p>The database type '. theme('placeholder', $db_type) .' is unsupported. Please use either <var>mysql</var> for MySQL databases or <var>pgsql</var> for PostgreSQL databases. The database information is in your <code>settings.php</code> file.</p>
+<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
+      exit;
     }
 
     $db_conns[$name] = db_connect($connect_url);

includes/database.mysql.inc

@@ -34,9 +34,36 @@ function db_connect($url) {
   //   server.
   // - 2 means CLIENT_FOUND_ROWS: return the number of found
   //   (matched) rows, not the number of affected rows.
-  $connection = mysql_connect($url['host'], $url['user'], $url['pass'], TRUE, 2) or die(mysql_error());
+  $connection = @mysql_connect($url['host'], $url['user'], $url['pass'], TRUE, 2);
+  if (!$connection) {
+    drupal_maintenance_theme();
+    drupal_set_title('Unable to connect to database server');
+    print theme('maintenance_page', '<p>This either means that the username and password information in your <code>settings.php</code> file is incorrect or we can\'t contact the MySQL database server. This could mean your hosting provider\'s database server is down.</p>
+<p>The MySQL error was: '. theme('placeholder', mysql_error()) .'.</p>
+<p>Currently, the username is '. theme('placeholder', $url['user']) .' and the database server is '. theme('placeholder', $url['host']) .'.</p>
+<ul>
+  <li>Are you sure you have the correct username and password?</li>
+  <li>Are you sure that you have typed the correct hostname?</li>
+  <li>Are you sure that the database server is running?</li>
+</ul>
+<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
+    exit;
+  }
 
-  mysql_select_db(substr($url['path'], 1)) or die('unable to select database');
+  if (!mysql_select_db(substr($url['path'], 1))) {
+    drupal_maintenance_theme();
+    drupal_set_title('Unable to select database');
+    print theme('maintenance_page', '<p>We were able to connect to the MySQL database server (which means your username and password is okay) but not able to select the database.</p>
+<p>The MySQL error was: '. theme('placeholder', mysql_error()) .'.</p>
+<p>Currently, the database is '. theme('placeholder', substr($url['path'], 1)) .'. The username is '. theme('placeholder', $url['user']) .' and the database server is '. theme('placeholder', $url['host']) .'.</p>
+<ul>
+  <li>Are you sure you have the correct database name?</li>
+  <li>Are you sure the database exists?</li>
+  <li>Are you sure the username has permission to access the database?</li>
+</ul>
+<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
+    exit;
+  }
 
   return $connection;
 }

includes/database.pgsql.inc

@@ -25,7 +25,32 @@ function db_connect($url) {
 
   $conn_string = ' user='. $url['user'] .' dbname='. substr($url['path'], 1) .' password='. $url['pass'] . ' host=' . $url['host'];
   $conn_string .= isset($url['port']) ? ' port=' . $url['port'] : '';
-  $connection = pg_connect($conn_string) or die(pg_last_error());
+
+  // pg_last_error() does not return a useful error message for database
+  // connection errors. We must turn on error tracking to get at a good error
+  // message, which will be stored in $php_errormsg.
+  $track_errors_previous = ini_get('track_errors');
+  ini_set('track_errors', 1);
+
+  $connection = @pg_connect($conn_string);
+  if (!$connection) {
+    drupal_maintenance_theme();
+    drupal_set_title('Unable to connect to database');
+    print theme('maintenance_page', '<p>This either means that the database information in your <code>settings.php</code> file is incorrect or we can\'t contact the PostgreSQL database server. This could mean your hosting provider\'s database server is down.</p>
+<p>The PostgreSQL error was: '. theme('placeholder', decode_entities($php_errormsg)) .'</p>
+<p>Currently, the database is '. theme('placeholder', substr($url['path'], 1)) .', the username is '. theme('placeholder', $url['user']) .', and the database server is '. theme('placeholder', $url['host']) .'.</p>
+<ul>
+  <li>Are you sure you have the correct username and password?</li>
+  <li>Are you sure that you have typed the correct hostname?</li>
+  <li>Are you sure you have the correct database name?</li>
+  <li>Are you sure that the database server is running?</li>
+</ul>
+<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
+    exit;
+  }
+
+  // Restore error tracking setting
+  ini_set('track_errors', $track_errors_previous);
 
   return $connection;
 }

includes/theme.inc

@@ -160,7 +160,7 @@ function list_theme_engines($refresh = FALSE) {
 function theme() {
   global $theme, $theme_engine;
 
-  if (!$theme) {
+  if ($theme === NULL) {
     // Initialize the enabled theme.
     $theme = init_theme();
   }
@@ -440,6 +440,31 @@ function theme_page($content) {
   return $output;
 }
 
+function theme_maintenance_page($content) {
+  drupal_set_header('Content-Type: text/html; charset=utf-8');
+  theme('add_style', 'misc/drupal.css');
+  theme('add_style', 'misc/maintenance.css');
+  $output = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n";
+  $output .= '<html xmlns="http://www.w3.org/1999/xhtml">';
+  $output .= '<head>';
+  $output .= '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />';
+  $output .= ' <title>'. drupal_get_title() .'</title>';
+  $output .= theme_get_styles();
+  $output .= '</head>';
+  $output .= '<body>';
+  $output .= '<h1>' . drupal_get_title() . '</h1>';
+
+  $output .= theme('status_messages');
+
+  $output .= "\n<!-- begin content -->\n";
+  $output .= $content;
+  $output .= "\n<!-- end content -->\n";
+
+  $output .= '</body></html>';
+
+  return $output;
+}
+
 /**
  * Returns themed set of status and/or error messages.  The messages are grouped
  * by type.

includes/unicode.inc

@@ -5,6 +5,13 @@ define('UNICODE_ERROR', -1);
 define('UNICODE_SINGLEBYTE', 0);
 define('UNICODE_MULTIBYTE', 1);
 
+/**
+ * Wrapper around _unicode_check().
+ */
+function unicode_check() {
+  $GLOBALS['multibyte'] = _unicode_check();
+}
+
 /**
  * Perform checks about Unicode support in PHP, and set the right settings if
  * needed.
@@ -16,7 +23,7 @@ define('UNICODE_MULTIBYTE', 1);
  * @param $errors
  *   Whether to report any fatal errors with form_set_error().
  */
-function unicode_check($errors = false) {
+function _unicode_check($errors = false) {
   // Set the standard C locale to ensure consistent, ASCII-only string handling.
   setlocale(LC_CTYPE, 'C');
 
@@ -70,7 +77,7 @@ function unicode_check($errors = false) {
  * Return the required Unicode status and errors for admin/settings.
  */
 function unicode_settings() {
-  $status = unicode_check(true);
+  $status = _unicode_check(true);
   $options = array(UNICODE_SINGLEBYTE => t('Standard PHP: operations on Unicode strings are emulated on a best-effort basis. Install the <a href="%url">PHP mbstring extension</a> for improved Unicode support.', array('%url' => 'http://www.php.net/manual/nl/ref.mbstring.php')),
                    UNICODE_MULTIBYTE => t('Multi-byte: operations on Unicode strings are supported through the <a href="%url">PHP mbstring extension</a>.', array('%url' => 'http://www.php.net/manual/nl/ref.mbstring.php')),
                    UNICODE_ERROR => t('Invalid: the current configuration is incompatible with Drupal.'));

misc/maintenance.css

@@ -0,0 +1,19 @@
+body {
+  background: url(druplicon.png) 4.2em 4em no-repeat #fff;
+  color: #000;
+  border: 1px solid #bbb;
+  margin: 3em;
+  padding: 1em 1em 1em 128px;
+}
+h1 {
+  margin: 1.6em 0 1.1em 0;
+  font-family: sans-serif;
+}
+:link {
+  color: #0073ba;
+  font-weight: bold;
+}
+:visited {
+  color: #004975;
+  font-weight: bold;
+}