Fix farmOS v1 geometry longitudes per https://github.com/farmOS/farmOS/issues/33

fix_longitudes.php

<?php

// Load GeoPHP.
geophp_load();

// Function for recursively fixing the longitude points within a Geometry.
function recursive_fix_lon(&$feature) {
  $fixed = FALSE;
  if ($feature->geometryType() == 'Point' && !empty($feature->coords[0])) {
    $lon = &$feature->coords[0];
    $lon = fmod($lon, 360);
    if ($lon < -180) {
      $lon += 360;
      $fixed = TRUE;
    }
    elseif ($lon > 180) {
      $lon -= 360;
      $fixed = TRUE;
    }
  }
  elseif ($feature->geometryType() != 'Point' && !empty($feature->components)) {
    foreach ($feature->components as $component) {
      if (recursive_fix_lon($component)) {
        $fixed = TRUE;
      }
    }
  }
  return $fixed;
}

// Load a list of entities with a non-empty geometry field.
$query = new EntityFieldQuery();
$query->fieldCondition('field_farm_geofield', 'geom', '', '!=')->addMetaData('account', user_load(1));
$result = $query->execute();

// Iterate through the list.
$fixed_entities = 0;
foreach ($result as $entity_type => $data) {
  $entity_ids = array_keys($data);
  foreach ($entity_ids as $entity_id) {

    // Load the entity.
    $load = entity_load($entity_type, array($entity_id));
    $entity = reset ($load);

    // Iterate through the geometries.
    if (!empty($entity->field_farm_geofield[LANGUAGE_NONE])) {
      foreach ($entity->field_farm_geofield[LANGUAGE_NONE] as &$value) {
        if (!empty($value['geom'])) {

          // Load the geometry.
          $features = geoPHP::load($value['geom'], 'wkt');

          // Fix the longitude points.
          $fixed = recursive_fix_lon($features);

          // If points were fixed, save it.
          if ($fixed) {
            $features->setGeos(NULL);
            $value = geofield_get_values_from_geometry($features);
            entity_save($entity_type, $entity);
            $fixed_entities++;
          }
        }
      }
    }
  }
}

drupal_set_message('Fixed ' . $fixed_entities . ' entitites');

If you need a version of this for farmOS v2, see: https://gist.github.com/mstenta/fbc912cb0e41f6af4f32b22b742009c7