griditems with x=0 placement fix

fix for #1054
* had incorrect check for 0 value (valid) when sorting objects. Checking NaN instead.
* this was introduced when fixing #1017

Author: Alain Dumesny

doc/CHANGES.md

@@ -28,7 +28,8 @@ Change log
 - add `gridstack.poly.js` for IE and older browsers, removed `core-js` lib from samples (<1k vs 85k), and all IE8 mentions ([#1061](https://github.com/gridstack/gridstack.js/pull/1061)).
 - add `jquery-ui.js` (and min.js) as minimal subset we need (55k vs 248k), which is now part of `gridstack.all.js`. Include individual parts if you need your own lib instead of all.js
 ([#1064](https://github.com/gridstack/gridstack.js/pull/1064)).
-- changed jquery dep to lowest we can use (>=1.8) ([#629](https://github.com/gridstack/gridstack.js/issues/629)).
+- changed jquery dependency to lowest we can use (>=1.8) ([#629](https://github.com/gridstack/gridstack.js/issues/629)).
+- fix for griditems with x=0 placement wrong order (introduced for #1017) ([#1054](https://github.com/gridstack/gridstack.js/issues/1054)).
 
 ## v0.5.3 (2019-11-20)
 

src/gridstack.js

@@ -801,11 +801,12 @@
       this.container.children('.' + this.opts.itemClass + ':not(.' + this.opts.placeholderClass + ')')
         .each(function(index, el) {
           el = $(el);
+          var x = parseInt(el.attr('data-gs-x'));
+          var y = parseInt(el.attr('data-gs-y'));
           elements.push({
             el: el,
-            // if x,y are missing (autoPosition) add them to end of list - keep their respective DOM order
-            i: (parseInt(el.attr('data-gs-x')) || 100) +
-              (parseInt(el.attr('data-gs-y')) || 100) * _this.opts.column
+            // if x,y are missing (autoPosition) add them to end of list - but keep their respective DOM order
+            i: (Number.isNaN(x) ? 1000 : x) + (Number.isNaN(y) ? 1000 : y) * _this.opts.column
           });
         });
       Utils.sortBy(elements, function(x) { return x.i; }).forEach(function(item) {