[Table] Improved sorting in table for demo EnhancedTable (mui#12736)

* improved table sorting logic

* improved table sorting logic

docs/src/pages/demos/tables/EnhancedTable.js

@@ -35,6 +35,16 @@ function desc(a, b, orderBy) {
   return 0;
 }
 
+function stableSort(array, cmp) {
+  const stabilizedThis = array.map((el, index) => [el, index]);
+  stabilizedThis.sort((a, b) => {
+    const order = cmp(a[0], b[0]);
+    if (order !== 0) return order;
+    return a[1] - b[1];
+  });
+  return stabilizedThis.map(el => el[0]);
+}
+
 function getSorting(order, orderBy) {
   return order === 'desc' ? (a, b) => desc(a, b, orderBy) : (a, b) => -desc(a, b, orderBy);
 }
@@ -282,8 +292,7 @@ class EnhancedTable extends React.Component {
               rowCount={data.length}
             />
             <TableBody>
-              {data
-                .sort(getSorting(order, orderBy))
+              {stableSort(data, getSorting(order, orderBy))
                 .slice(page * rowsPerPage, page * rowsPerPage + rowsPerPage)
                 .map(n => {
                   const isSelected = this.isSelected(n.id);