An ExtJS paging toolbar override that fixes the incorrect paging behaviour in an edge case. Compatible with ExtJS 4.2.1.

Paging.override.js

/**
 * A paging toolbar override that fixes the incorrect paging behaviour when navigating 
 * to a certain page (where page no. > 1), doing a remote load of data (i.e.: filtering
 * data) and size of the remote data is less than store's defined pageSize.
 *
 * Compatible with ExtJS 4.2.1.
 *
 * @class Ext.toolbar.Paging
 * @override
 * @author Bostjan Rihter <bostjan.rihter@gmail.com>
 */
Ext.override(Ext.toolbar.Paging, {
  getPageData: function () {
    var store = this.store,
      totalCount = store.getTotalCount(),
      currentPage = store.currentPage,
      pageCount = Math.ceil(totalCount / store.pageSize),
      fromRecord = ((store.currentPage - 1) * store.pageSize) + 1,
      toRecord = Math.min(store.currentPage * store.pageSize, totalCount);

    //#region override
    if (totalCount <= store.pageSize) {
      currentPage = 1;
      fromRecord = 1;
    }
    //#endregion

    return {
      total: totalCount,
      currentPage: currentPage,
      pageCount: pageCount,
      fromRecord: fromRecord,
      toRecord: toRecord
    };
  }
});