Uglify JS bug

input.js

// Reduced/boiled down from a webpack bundle, obviously not the real thing
var zing = {};

(function foo(module, exports, __webpack_require__) {
  "use strict";

  exports.default = sortableContainer;

  function sortableContainer(WrappedComponent) {
    var _class,
      _temp,
      win = {};
    return (
      (_temp = _class = (function(_Component) {
        function _createClass(unused, methods) {
          var output = {};
          methods.forEach(function(method) {
            output[method.key] = method.value;
          });
          return output;
        }
        function _class(input) {
          return input;
        }
        return _createClass(_class, [
          {
            key: "animateNodes",
            value: function animateNodes() {
              var _props3 = this.props,
                nodes = [],
                transitionDuration = _props3.transitionDuration,
                hideSortableGhost = _props3.hideSortableGhost;

              var deltaScroll = {
                left: this.scrollContainer.scrollLeft - this.initialScroll.left,
                top: this.scrollContainer.scrollTop - this.initialScroll.top
              };
              var sortingOffset = {
                left:
                  this.offsetEdge.left + this.translate.x + deltaScroll.left,
                top: this.offsetEdge.top + this.translate.y + deltaScroll.top
              };
              var scrollDifference = {
                top: win.pageYOffset - this.initialWindowScroll.top,
                left: win.pageXOffset - this.initialWindowScroll.left
              };

              for (var i = 0, len = nodes.length; i < len; i++) {
                var node = nodes[i].node;

                var index = node.sortableInfo.index;
                var width = node.offsetWidth;
                var height = node.offsetHeight;
                var offset = {
                  width: this.width > width ? width / 2 : this.width / 2,
                  height: this.height > height ? height / 2 : this.height / 2
                };

                if (this.axis.y) {
                  if (
                    index < this.index &&
                    ((sortingOffset.left +
                      scrollDifference.left -
                      offset.width <=
                      edgeOffset.left &&
                      sortingOffset.top + scrollDifference.top <=
                        edgeOffset.top + offset.height) ||
                      sortingOffset.top +
                        scrollDifference.top +
                        offset.height <=
                        edgeOffset.top)
                  ) {
                    // Do something
                  }
                }
              }

              return "it ran without issues";
            }
          }
        ]);
      })()),
      _temp
    );
  }
})({}, zing);

var f = zing.default();
console.log(
  f.animateNodes.call({
    axis: { y: 13 },
    height: 300,
    index: 2,
    initialScroll: { left: 0, top: 0 },
    initialWindowScroll: { left: 0, top: 0 },
    offsetEdge: { left: 0, top: 0 },
    props: { transitionDuration: 300, hideSortableGhost: false },
    scrollContainer: { scrollLeft: 0, scrollTop: 0 },
    translate: { x: 0, y: 0 },
    width: 200
  })
);

// Output: 'it ran without issues'

output.js

var zing={};!function(module,exports,__webpack_require__){"use strict";exports.default=function(WrappedComponent){var win={};return function(unused,methods){var output={};return[{key:"animateNodes",value:function(){for(var _props3=this.props,nodes=[],sortingOffset_left=(_props3.transitionDuration,_props3.hideSortableGhost,this.scrollContainer.scrollLeft,this.initialScroll.left,this.scrollContainer.scrollTop,this.initialScroll.top,this.offsetEdge.left+this.translate.x+deltaScroll.left),sortingOffset_top=this.offsetEdge.top+this.translate.y+deltaScroll.top,scrollDifference_top=win.pageYOffset-this.initialWindowScroll.top,scrollDifference_left=win.pageXOffset-this.initialWindowScroll.left,i=0,len=nodes.length;i<len;i++){var node=nodes[i].node,index=node.sortableInfo.index,width=node.offsetWidth,height=node.offsetHeight,offset_width=this.width>width?width/2:this.width/2,offset_height=this.height>height?height/2:this.height/2;this.axis.y&&index<this.index&&(sortingOffset_left+scrollDifference_left-offset_width<=edgeOffset.left&&sortingOffset_top+scrollDifference_top<=edgeOffset.top+offset_height||edgeOffset.top)}return"it ran without issues"}}].forEach(function(method){output[method.key]=method.value}),output}()}}(0,zing);var f=zing.default();console.log(f.animateNodes.call({axis:{y:13},height:300,index:2,initialScroll:{left:0,top:0},initialWindowScroll:{left:0,top:0},offsetEdge:{left:0,top:0},props:{transitionDuration:300,hideSortableGhost:!1},scrollContainer:{scrollLeft:0,scrollTop:0},translate:{x:0,y:0},width:200}));

// Output:
/*
ReferenceError: deltaScroll is not defined
    at Object.value (/home/espenh/webdev/some-project/test.min.js:1:535)
    at Object.<anonymous> (/home/espenh/webdev/some-project/test.min.js:1:1348)
    at Module._compile (module.js:641:30)
    at Object.Module._extensions..js (module.js:652:10)
    at Module.load (module.js:560:32)
    at tryModuleLoad (module.js:503:12)
    at Function.Module._load (module.js:495:3)
    at Function.Module.runMain (module.js:682:10)
    at startup (bootstrap_node.js:191:16)
    at bootstrap_node.js:613:3

*/