Function "closest" adds extra points to layers

[aver-ua]

There is an issue, described in title
Please see this plunk
Click to set markers and see in console how latlngs of polygon grows.
It seems to me, that it happens because function "slice()" does not makes deep copy for nested arrays (line 205 in source)

[mdartic]

You're right.
Check 0.7.2, I let you close the issue if it's ok for you.

[aver-ua]

@mdartic,
I cheked 0.7.2 in my app, but I got an errors "Uncaught TypeError: Converting circular structure to JSON".
Simple code like in my previous post works correct, but more complex - no.
I try to figure out what was going on...

[aver-ua]

@mdartic,
My investigation shows, that "closest" raises errors "Uncaught TypeError: Converting circular structure to JSON" in conjuction with Leaflet.Editable, Leaflet.Snap and GeoJSON layers.
I can't provide (yet) test case (plunk, for example), that illustrates this issue.
But I found workaround for me. I changed the line in source
latlngs = JSON.parse(JSON.stringify(layer.getLatLngs().slice(0)));
to

function deepClone(arr) {
  var len = arr.length;
  var newArr = new Array(len);
  for (var i=0; i<len; i++) {
    if ((Array.isArray(arr[i]))&&(!(arr[i] instanceof L.LatLng))) 
      newArr[i] = deepClone(arr[i]);
    else 
      newArr[i] = arr[i].clone();
  }
  return newArr;
}       
latlngs=deepClone(layer.getLatLngs().slice(0));

[peterlawless]

@aver-ua thanks for the fix, worked perfectly for me.

[mdartic]

@aver-ua sorry to be so late, but do you have now a small example to be integrate in a test ?
could be useful to remember this after fixing it.
if not, I'll integrate your deepClone method.

[aver-ua]

@mdartic sorry to be so so so late...
i found in my leaflet.geometryutil.js following code for closest function

closest: function (map, layer, latlng, vertices) {

function extractLatLngs(arr,latlngs) {
if ((arr instanceof Array)&&(arr[0] instanceof L.LatLng)) {
    for (var j=0;j<arr.length;j++)
     latlngs.push(arr[j]);
    latlngs.push(arr[0]);// we need also last segment!
}
else 
 for (var i=0;i<arr.length;i++)
  extractLatLngs(arr[i],latlngs);
} 

    if (typeof layer.getLatLngs != 'function')
        layer = L.polyline(layer);
	
    var latlngs = [],
        mindist = Infinity,
        result = null,
        i, n, distance;
		
	if (layer instanceof L.Polygon) {
	    extractLatLngs(layer.getLatLngs(),latlngs);			
	} else latlngs=layer.getLatLngs().slice(0);


    // Lookup vertices
    if (vertices) {
        for(i = 0, n = latlngs.length; i < n; i++) {
            var ll = latlngs[i];
            distance = L.GeometryUtil.distance(map, latlng, ll);
            if (distance < mindist) {
                mindist = distance;
                result = ll;
                result.distance = distance;
            }
        }
        return result;
    }

    // Keep the closest point of all segments
    for (i = 0, n = latlngs.length; i < n-1; i++) {
        var latlngA = latlngs[i],
            latlngB = latlngs[i+1];                
        distance = L.GeometryUtil.distanceSegment(map, latlng, latlngA, latlngB);
        if (distance <= mindist) {
            mindist = distance;
            result = L.GeometryUtil.closestOnSegment(map, latlng, latlngA, latlngB);
            result.distance = distance;
        }
    }
    return result;
}

moreover, the previous version with deepClone is commented out.
and it worked for more than 5 years without any problems. there is no problem with "extra points" and GeoJSON layers.
i don't know who is an author of this code... it seems to me that it's not me.