diff --git a/content.module b/content.module
index 1b73434f0d55272d4976c5c8fd1a3cac186188f7..c6cab76a9d12327cbc9cb32a01a8fe0550f68290 100644
--- a/content.module
+++ b/content.module
@@ -789,11 +789,23 @@ function _content_field_invoke_default($op, &$node, $teaser = NULL, $page = NULL
   }
   elseif (count($type['fields'])) {
     foreach ($type['fields'] as $field) {
-      $node_field = isset($node->$field['field_name']) ? $node->$field['field_name'] : array();
+      $items = isset($node->$field['field_name']) ? $node->$field['field_name'] : array();
+
+      // Don't save empty items.
+      if ($op == 'presave') {
+        foreach ((array) $items as $delta => $item) {
+          $widget_types = _content_widget_types();
+          $module = $widget_types[$field['widget']['type']]['module'];
+          $is_empty = $module .'_content_is_empty';
+          if ($delta > 0 && $is_empty($item, $field)) {
+            unset($items[$delta]);
+          }
+        }
+      }
 
       $db_info = content_database_info($field);
       if (count($db_info['columns'])) {
-        $result = content_field($op, $node, $field, $node_field, $teaser, $page);
+        $result = content_field($op, $node, $field, $items, $teaser, $page);
         if (is_array($result)) {
           $return = array_merge($return, $result);
         }
@@ -802,7 +814,7 @@ function _content_field_invoke_default($op, &$node, $teaser = NULL, $page = NULL
         }
       }
       if (isset($node->$field['field_name'])) {
-        $node->$field['field_name'] = $node_field;
+        $node->$field['field_name'] = $items;
       }
     }
   }
diff --git a/content_views.inc b/content_views.inc
index 708545ba55412cac6d4f4614dbd05417fec4d4fd..2bb14e55fa8273b60f8c97b96eb0772acfe37ce9 100644
--- a/content_views.inc
+++ b/content_views.inc
@@ -144,6 +144,8 @@ function content_views_field_handler_group($field_info, $field_data, $value, $da
     foreach ($field_info['content_db_info']['columns'] as $column => $attributes) {
       $query_columns[] = "node_data_$field[field_name].$attributes[column] AS $column";
     }
+    // Add node.nid to the beginning of the list to keep db_rewrite_sql()
+    // from mistakenly adding DISTINCT to nodereference fields.
     $query = "SELECT node.nid, ". implode(', ', $query_columns) .
              " FROM {node} node".
              " LEFT JOIN {". $field_info['content_db_info']['table'] ."} node_data_$field[field_name] ON node.vid = node_data_$field[field_name].vid".
diff --git a/nodereference.module b/nodereference.module
index 22744980441e820b138edc75fc7b6b4a06a6d179..7beb9fdd15a05c631132ad74ab6d32b087d95cf4 100644
--- a/nodereference.module
+++ b/nodereference.module
@@ -153,19 +153,17 @@ function nodereference_field($op, &$node, $field, &$items, $teaser, $page) {
         }
       }
       return;
+  }
+}
 
-    // Don't save empty items.
-    case 'presave':
-      if (is_array($items)) {
-        foreach ($items as $delta => $item) {
-          if ($delta > 0 && empty($item)) {
-            unset($items[$delta]);
-            unset($node->{$field['field_name'][$delta]});
-          }
-        }
-      }
-      break;
+/**
+ * Implementation of hook_content_is_empty().
+ */
+function nodeference_content_is_empty($item, $field) {
+  if (empty($item['nid'])) {
+    return TRUE;
   }
+  return FALSE;
 }
 
 /**
diff --git a/number.module b/number.module
index df6ed3d1988d0e52a9e3bd98f03447d7a5fe31f0..46ea275bbd08cd3647ecff7c1ef1aa9ebae1acfc 100644
--- a/number.module
+++ b/number.module
@@ -167,19 +167,17 @@ function number_field($op, &$node, $field, &$items, $teaser, $page) {
         }
       }
       break;
+  }
+}
 
-    // Don't save empty items.
-    case 'presave':
-      if (is_array($items)) {
-        foreach ($items as $delta => $item) {
-          if ($delta > 0 && empty($item)) {
-            unset($items[$delta]);
-            unset($node->{$field['field_name'][$delta]});
-          }
-        }
-      }
-      break;
+/**
+ * Implementation of hook_content_is_empty().
+ */
+function number_content_is_empty($item, $field) {
+  if (empty($item['value'])) {
+    return TRUE;
   }
+  return FALSE;
 }
 
 /**
diff --git a/text.module b/text.module
index fc59f133a07825b28869fd0e9fc387ea44f5b8fe..832109bae80f71bc81265e3f9e8f02e6e1042672 100644
--- a/text.module
+++ b/text.module
@@ -153,20 +153,19 @@ function text_field($op, &$node, $field, &$items, $teaser, $page) {
       }
       break;
 
-    // Don't save empty items.
-    case 'presave':
-      if (is_array($items)) {
-        foreach ($items as $delta => $item) {
-          if ($delta > 0 && empty($item)) {
-            unset($items[$delta]);
-            unset($node->{$field['field_name'][$delta]});
-          }
-        }
-      }
-      break;
   }
 }
 
+/**
+ * Implementation of hook_content_is_empty().
+ */
+function text_content_is_empty($item, $field) {
+  if (empty($item['value'])) {
+    return TRUE;
+  }
+  return FALSE;
+}
+
 /**
  * Implementation of hook_field_formatter_info().
  */
diff --git a/userreference.module b/userreference.module
index 0f1e037ac47e4ee704deec6441a057d8300f6ebc..0ace4e5aa7c3d34603e39d71ecdb0cef8fb9af27 100644
--- a/userreference.module
+++ b/userreference.module
@@ -77,19 +77,17 @@ function userreference_field($op, &$node, $field, &$items, $teaser, $page) {
         }
       }
       return;
+  }
+}
 
-    // Don't save empty items.
-    case 'presave':
-      if (is_array($items)) {
-        foreach ($items as $delta => $item) {
-          if ($delta > 0 && empty($item)) {
-            unset($items[$delta]);
-            unset($node->{$field['field_name'][$delta]});
-          }
-        }
-      }
-      break;
+/**
+ * Implementation of hook_content_is_empty().
+ */
+function userreference_content_is_empty($item, $field) {
+  if (empty($item['uid'])) {
+    return TRUE;
   }
+  return FALSE;
 }
 
 /**