TypeError: Cannot call method 'replace' of undefined

[strk]

Attempts to render the following MML results in an exception being thrown.
I'm not sure if exception throwing is tolerated (I remember someone once told me carto was not supposed to throw?)

This happens as of commit 21be5fb (current master)

{
    "srs":"+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
    "Stylesheet": [
      {"id":"tile_style"}
    ],
    "Layer": [{
      "clear_label_cache": false,
      "queryable": false,
      "maximum_scale_denominator": 1.7976931348623157e+308,
      "minimum_scale_denominator":0,
      "datasource": {
        "type":"vector"
      },
      "styles": ["layer"],
      "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
      "active": true,
      "name": "layer"
    }]
}

[strk]

I think the problem is in the missing data element in the Stylesheet only element.

[strk]

I would provide a testcase but I cannot due to #429

[nebulon42]

Yes, that's it. The problem is actually in https://github.com/mapbox/carto/blob/master/lib/carto/renderer.js#L93 where the parser is called with s.data, which is undefined. No relation to the mentioned commit though, as it happened also before.

[nebulon42]

Related to #367.