Steps to Reproduce:

Create a grid with datatype: 'json' and do the following:

1) Load data to the grid using the addJSONData method.

2)Perform local search. This is how I am currently doing it:

   var grid = $('testGrid');

   var postdata = grid.jqGrid('getGridParam', 'postData');

   $.extend(postdata,

     {

filters: '',

searchField: 'colname'

searchOper: 'eq'

searchString: 'test'

     });

     grid.jqGrid('setGridParam', {search: true, postData: postdata });

     grid.trigger('reloadGrid', [{page: 1}]);

3) You will notice that the rows disappear instead of being filtered. Now change the grid's datatype to 'jsonstring' and try again. You will notice that the rows are properly filtered.

I have found the bug in the grid.base.js file in version 3.8.2 at line 1167:

locdata = (ts.p.datatype != "local" && ts.p.loadonce) || ts.p.datatype == "jsonstring";

Changing the line to the following causes it to work with datatype 'json'

locdata = (ts.p.datatype != "local" && ts.p.loadonce) || ts.p.datatype == "jsonstring" || ts.p.datatype == "json";

jqGrid version: 3.8.2