Symptom

Invalid out-of-bounds tiles are requested from the server, resulting in 404 errors in the console and the default image-couldn't-be-loaded rectangles being displayed instead of no tiles.

Trigger

This problem happens when a layer has both the noWrap and the bounds options.

Visual comparison

The layers are defined with noWrap: true and bounds: [[-90, -180], [90, 180]]. Incorrect behavior on the left, fixed one on the right.

Bug

The following function located inside GridLayer does not respect the noWrap option: map.wrapLatLng(...) is always called.

_tileCoordsToBounds: function (coords) {

    // ...

    nw = map.wrapLatLng(map.unproject(nwPoint, coords.z)),
    se = map.wrapLatLng(map.unproject(sePoint, coords.z));

    return new L.LatLngBounds(nw, se);
},

Fix

If the noWrap option is set on the layer, map.wrapLatLng should not be called.

Explanation

The _tileCoordsToBounds(...) function is called by _isValidTile(...), which relies on it to validate a tile by checking that it is in the user-defined bounds (if any), as seen below.

_isValidTile: function (coords) {

    // ...

    if (!this.options.bounds) { return true; }

    // don't load tile if it doesn't intersect the bounds in options
    var tileBounds = this._tileCoordsToBounds(coords);
    return L.latLngBounds(this.options.bounds).overlaps(tileBounds);
},

Workaround (until a fix is released)

You can patch the layer._tileCoordsToBounds function on your layers, changing the offending call.

Version

I am facing this bug in version v1.0.0-rc.1 and the few changes to this file in master are completely unrelated.