[gh-431] Merge branch 'issue-431' into develop

sites/all/modules/unl/cron.php

@@ -393,7 +393,7 @@ function unl_add_site_to_htaccess($site_id, $site_path, $is_alias) {
                  . $stub_token
                  . substr($htaccess, $stub_pos + strlen($stub_token));
 
-  file_put_contents(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
+  _unl_file_put_contents_atomic(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
 }
 
 function unl_remove_site_from_htaccess($site_id, $is_alias) {
@@ -420,7 +420,7 @@ function unl_remove_site_from_htaccess($site_id, $is_alias) {
   $new_htaccess = substr($htaccess, 0, $start_pos)
                 . substr($htaccess, $end_pos + strlen($site_end_token))
                 ;
-  file_put_contents(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
+  _unl_file_put_contents_atomic(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
 }
 
 function unl_add_page_alias_to_htaccess($site_id, $host, $path, $to_uri) {
@@ -441,7 +441,7 @@ function unl_add_page_alias_to_htaccess($site_id, $host, $path, $to_uri) {
                 . $stub_token
                 . substr($htaccess, $stub_pos + strlen($stub_token));
 
-  file_put_contents(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
+  _unl_file_put_contents_atomic(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
 }
 
 function unl_remove_page_alias_from_htaccess($site_id) {
@@ -461,7 +461,7 @@ function unl_remove_page_alias_from_htaccess($site_id) {
   $new_htaccess = substr($htaccess, 0, $start_pos)
                 . substr($htaccess, $end_pos + strlen($site_end_token))
                 ;
-  file_put_contents(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
+  _unl_file_put_contents_atomic(DRUPAL_ROOT . '/.htaccess', $new_htaccess);
 }
 
 function unl_add_alias_to_sites_php($site_uri, $base_uri, $path, $alias_id) {
@@ -490,7 +490,7 @@ function unl_add_alias_to_sites_php($site_uri, $base_uri, $path, $alias_id) {
   $old_real_site_dir = unl_get_sites_subdir($alias_uri);
   $new_sites_php = str_replace("'".$old_real_site_dir."'", "'".$real_site_dir."'", $new_sites_php);
 
-  file_put_contents(DRUPAL_ROOT . '/sites/sites.php', $new_sites_php);
+  _unl_file_put_contents_atomic(DRUPAL_ROOT . '/sites/sites.php', $new_sites_php);
 }
 
 function unl_remove_alias_from_sites_php($alias_id) {
@@ -510,7 +510,7 @@ function unl_remove_alias_from_sites_php($alias_id) {
   $new_sites_php = substr($sites_php, 0, $start_pos)
                  . substr($sites_php, $end_pos + strlen($site_end_token))
                  ;
-  file_put_contents(DRUPAL_ROOT . '/sites/sites.php', $new_sites_php);
+  _unl_file_put_contents_atomic(DRUPAL_ROOT . '/sites/sites.php', $new_sites_php);
 }
 
 function unl_require_writable($path) {
@@ -518,3 +518,38 @@ function unl_require_writable($path) {
     throw new Exception('The file "' . $path . '" needs to be writable and is not.');
   }
 }
+
+/**
+ * A drop-in replacement for file_put_contents that will atomically put the new file into place.
+ * This additionally requires you to have write access to the directory that will contain the file.
+ * @see file_put_contents
+ */
+function _unl_file_put_contents_atomic($filename, $data, $flags = 0, $context = NULL) {
+  // Create a temporary file with a simalar name in the destination directory.
+  $tempfile = tempnam(dirname($filename), basename($filename) . '_');
+  if ($tempfile === FALSE) {
+    return FALSE;
+  }
+  // Fix the permissions on the file since they will be 0600.
+  if (file_exists($filename)) {
+    $stat = stat($filename);
+    chmod($tempfile, $stat['mode']);
+  } else {
+    chmod($tempfile, 0666 & ~umask());
+  }
+  
+  // Do the actual file_put contents
+  $bytes = file_put_contents($tempfile, $data, $flags, $context);
+  if ($bytes === FALSE) {
+    unlink($tempfile);
+    return FALSE;
+  }
+  
+  // Move the new file into place atomically.
+  if (!rename($tempfile, $filename)) {
+    unlink($tempfile);
+    return FALSE;
+  }
+  
+  return $bytes;
+}