Fix: dt-api order() called with an empty array would cause a JS error

- Fixes DataTables/DataTables #800
- Its safe to check for `.length` on `orders` at this point since it can
  be either a number, an array or undefined. The number and undefined
  conditions have already been checked, so it must be an array (of
  whatever length).

.datatables-commit-sync

@@ -1 +1 @@
-7925dbe9b9a30dd339898670926e3fe89cd2db15
+91a3581a1c030835bead900b938ef07840f44ca5

media/js/jquery.dataTables.js

@@ -8841,7 +8841,7 @@
 			// Simple column / direction passed in
 			order = [ [ order, dir ] ];
 		}
-		else if ( ! $.isArray( order[0] ) ) {
+		else if ( order.length && ! $.isArray( order[0] ) ) {
 			// Arguments passed in (list of 1D arrays)
 			order = Array.prototype.slice.call( arguments );
 		}

media/js/jquery.dataTables.min.js

@@ -127,7 +127,7 @@ n;i++)l=j[i].nTr,f=j[i].anCells,l&&l.insertBefore(f[c],f[m]||null)}else h(G(b.ao
 j)),l,n=b.aoColumns.length,m,p,r,u,v,s;return $a("cell",d,function(a){var c=typeof a==="function";if(a===null||a===k||c){m=[];p=0;for(r=g.length;p<r;p++){l=g[p];for(u=0;u<n;u++){v={row:l,column:u};if(c){s=f[l];a(v,B(b,l,u),s.anCells?s.anCells[u]:null)&&m.push(v)}else m.push(v)}}return m}if(h.isPlainObject(a))return[a];c=i.filter(a).map(function(a,b){return{row:b._DT_CellIndex.row,column:b._DT_CellIndex.column}}).toArray();if(c.length||!a.nodeName)return c;s=h(a).closest("*[data-dt-row]");return s.length?
 [{row:s.data("dt-row"),column:s.data("dt-column")}]:[]},b,e)});var d=this.columns(b,c),e=this.rows(a,c),f,g,j,i,n,l=this.iterator("table",function(a,b){f=[];g=0;for(j=e[b].length;g<j;g++){i=0;for(n=d[b].length;i<n;i++)f.push({row:e[b][g],column:d[b][i]})}return f},1);h.extend(l.selector,{cols:b,rows:a,opts:c});return l});s("cells().nodes()","cell().node()",function(){return this.iterator("cell",function(a,b,c){return(a=a.aoData[b])&&a.anCells?a.anCells[c]:k},1)});p("cells().data()",function(){return this.iterator("cell",
 function(a,b,c){return B(a,b,c)},1)});s("cells().cache()","cell().cache()",function(a){a="search"===a?"_aFilterData":"_aSortData";return this.iterator("cell",function(b,c,d){return b.aoData[c][a][d]},1)});s("cells().render()","cell().render()",function(a){return this.iterator("cell",function(b,c,d){return B(b,c,d,a)},1)});s("cells().indexes()","cell().index()",function(){return this.iterator("cell",function(a,b,c){return{row:b,column:c,columnVisible:$(a,c)}},1)});s("cells().invalidate()","cell().invalidate()",
-function(a){return this.iterator("cell",function(b,c,d){ca(b,c,a,d)})});p("cell()",function(a,b,c){return bb(this.cells(a,b,c))});p("cell().data()",function(a){var b=this.context,c=this[0];if(a===k)return b.length&&c.length?B(b[0],c[0].row,c[0].column):k;jb(b[0],c[0].row,c[0].column,a);ca(b[0],c[0].row,"data",c[0].column);return this});p("order()",function(a,b){var c=this.context;if(a===k)return 0!==c.length?c[0].aaSorting:k;"number"===typeof a?a=[[a,b]]:h.isArray(a[0])||(a=Array.prototype.slice.call(arguments));
+function(a){return this.iterator("cell",function(b,c,d){ca(b,c,a,d)})});p("cell()",function(a,b,c){return bb(this.cells(a,b,c))});p("cell().data()",function(a){var b=this.context,c=this[0];if(a===k)return b.length&&c.length?B(b[0],c[0].row,c[0].column):k;jb(b[0],c[0].row,c[0].column,a);ca(b[0],c[0].row,"data",c[0].column);return this});p("order()",function(a,b){var c=this.context;if(a===k)return 0!==c.length?c[0].aaSorting:k;"number"===typeof a?a=[[a,b]]:a.length&&!h.isArray(a[0])&&(a=Array.prototype.slice.call(arguments));
 return this.iterator("table",function(b){b.aaSorting=a.slice()})});p("order.listener()",function(a,b,c){return this.iterator("table",function(d){Oa(d,a,b,c)})});p("order.fixed()",function(a){if(!a){var b=this.context,b=b.length?b[0].aaSortingFixed:k;return h.isArray(b)?{pre:b}:b}return this.iterator("table",function(b){b.aaSortingFixed=h.extend(!0,{},a)})});p(["columns().order()","column().order()"],function(a){var b=this;return this.iterator("table",function(c,d){var e=[];h.each(b[d],function(b,
 c){e.push([c,a])});c.aaSorting=e})});p("search()",function(a,b,c,d){var e=this.context;return a===k?0!==e.length?e[0].oPreviousSearch.sSearch:k:this.iterator("table",function(e){e.oFeatures.bFilter&&fa(e,h.extend({},e.oPreviousSearch,{sSearch:a+"",bRegex:null===b?!1:b,bSmart:null===c?!0:c,bCaseInsensitive:null===d?!0:d}),1)})});s("columns().search()","column().search()",function(a,b,c,d){return this.iterator("column",function(e,f){var g=e.aoPreSearchCols;if(a===k)return g[f].sSearch;e.oFeatures.bFilter&&
 (h.extend(g[f],{sSearch:a+"",bRegex:null===b?!1:b,bSmart:null===c?!0:c,bCaseInsensitive:null===d?!0:d}),fa(e,e.oPreviousSearch,1))})});p("state()",function(){return this.context.length?this.context[0].oSavedState:null});p("state.clear()",function(){return this.iterator("table",function(a){a.fnStateSaveCallback.call(a.oInstance,a,{})})});p("state.loaded()",function(){return this.context.length?this.context[0].oLoadedState:null});p("state.save()",function(){return this.iterator("table",function(a){ya(a)})});