Undefined index: tid in hs_taxonomy_field_formatter_prepare_view()

Reverting to beta3 solved the problem.

I believe it was caused by a Rule that sends an Views email. I'll try to get more info from the guy who wrote it.

@sistro: Okay, maybe it's just a Views thing. Can you post your view, please, so the developer can test with it?

With beta7:

Notice: Undefined index: tid in taxonomy_field_presave() (line 1900 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_field_presave() (line 1900 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_field_presave() (line 1900 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_build_node_index() (line 1964 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_build_node_index() (line 1964 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_build_node_index() (line 1964 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_build_node_index() (line 1964 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_build_node_index() (line 1964 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
Notice: Undefined index: tid in taxonomy_build_node_index() (line 1964 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).
PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'tid' cannot be null: INSERT INTO {taxonomy_index} (nid, tid, sticky, created) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3), (:db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7), (:db_insert_placeholder_8, :db_insert_placeholder_9, :db_insert_placeholder_10, :db_insert_placeholder_11), (:db_insert_placeholder_12, :db_insert_placeholder_13, :db_insert_placeholder_14, :db_insert_placeholder_15), (:db_insert_placeholder_16, :db_insert_placeholder_17, :db_insert_placeholder_18, :db_insert_placeholder_19), (:db_insert_placeholder_20, :db_insert_placeholder_21, :db_insert_placeholder_22, :db_insert_placeholder_23), (:db_insert_placeholder_24, :db_insert_placeholder_25, :db_insert_placeholder_26, :db_insert_placeholder_27), (:db_insert_placeholder_28, :db_insert_placeholder_29, :db_insert_placeholder_30, :db_insert_placeholder_31), (:db_insert_placeholder_32, :db_insert_placeholder_33, :db_insert_placeholder_34, :db_insert_placeholder_35), (:db_insert_placeholder_36, :db_insert_placeholder_37, :db_insert_placeholder_38, :db_insert_placeholder_39); Array ( [:db_insert_placeholder_0] => 37283 [:db_insert_placeholder_1] => 1330 [:db_insert_placeholder_2] => 0 [:db_insert_placeholder_3] => 1465303317 [:db_insert_placeholder_4] => 37283 [:db_insert_placeholder_5] => 1323 [:db_insert_placeholder_6] => 0 [:db_insert_placeholder_7] => 1465303317 [:db_insert_placeholder_8] => 37283 [:db_insert_placeholder_9] => 24 [:db_insert_placeholder_10] => 0 [:db_insert_placeholder_11] => 1465303317 [:db_insert_placeholder_12] => 37283 [:db_insert_placeholder_13] => [:db_insert_placeholder_14] => 0 [:db_insert_placeholder_15] => 1465303317 [:db_insert_placeholder_16] => 37283 [:db_insert_placeholder_17] => 120 [:db_insert_placeholder_18] => 0 [:db_insert_placeholder_19] => 1465303317 [:db_insert_placeholder_20] => 37283 [:db_insert_placeholder_21] => 126 [:db_insert_placeholder_22] => 0 [:db_insert_placeholder_23] => 1465303317 [:db_insert_placeholder_24] => 37283 [:db_insert_placeholder_25] => 170 [:db_insert_placeholder_26] => 0 [:db_insert_placeholder_27] => 1465303317 [:db_insert_placeholder_28] => 37283 [:db_insert_placeholder_29] => 171 [:db_insert_placeholder_30] => 0 [:db_insert_placeholder_31] => 1465303317 [:db_insert_placeholder_32] => 37283 [:db_insert_placeholder_33] => 172 [:db_insert_placeholder_34] => 0 [:db_insert_placeholder_35] => 1465303317 [:db_insert_placeholder_36] => 37283 [:db_insert_placeholder_37] => 174 [:db_insert_placeholder_38] => 0 [:db_insert_placeholder_39] => 1465303317 ) in taxonomy_build_node_index() (line 1981 of C:\wamp\www\Core7\modules\taxonomy\taxonomy.module).

The above patch makes no difference.

This is happening during node_save(). My code for invoking that is:

  $update_node = FALSE;

  // Get the fields that are in that group.
  $x = db_query("SELECT data FROM {field_group} "
    . "WHERE group_name = 'group_associated_tracker_details' "
    . "AND bundle = 'materials' ")->fetchField();
  $data = unserialize($x);

  // Get the Tracker from which to copy data.
  $tracker = node_load($node->field_tracker[LANGUAGE_NONE][0]['target_id']);

  // Check each field.
  foreach ($data['children'] as $field_name) {
    if ($field_name == 'field_tracker') {
      continue;
    }

    // If the Tracker has data and the Material does not, copy the data.
    if (isset($tracker->{$field_name}[LANGUAGE_NONE][0])
    && !isset($node->{$field_name}[LANGUAGE_NONE][0])) {
      $node->{$field_name} = $tracker->{$field_name};
      $update_node = TRUE;
    }
  }

  // If any fields changed, save the node.
  if ($update_node) {
    node_save($node);
    if ($redirect) {
      drupal_set_message(t('Tracker data merged.'));
      // Force redisplay.
      drupal_goto("node/$node->nid");
    }
  }

Nope, sorry.

Possibly related: #2831247: Undefined index

Patch in #22 (plus going to beta7) seems to fix both problems for me.