Fix regex nesting inheritance

lib/carto/tree/filterset.js

@@ -97,6 +97,9 @@ Object.defineProperty(tree.Filterset.prototype, 'addable', {
                 if (key + '<=' in this && this[key + '<='].val < value) return false;
                 return true;
 
+            case '=~':
+                return true;
+
             case '!=':
                 if (key + '=' in this) return (this[key + '='].val == value) ? false : null;
                 if (key + '!=' + value in this) return null;

test/rendering/regex_nest.mml

@@ -0,0 +1,14 @@
+{
+    "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": [
+        "regex_nest.mss"
+    ],
+    "Layer": [{
+        "name": "railway",
+        "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",
+        "Datasource": {
+            "file": "http://tilemill-data.s3.amazonaws.com/test_data/shape_demo.zip",
+            "type": "shape"
+        }
+    }]
+}

test/rendering/regex_nest.mss

@@ -0,0 +1,6 @@
+#railway[foo='bar'] {
+    [name =~ "East.*"] {
+        line-color: green;
+        line-width: 4;
+    }
+}

test/rendering/regex_nest.result

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE Map[]>
+<Map 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" maximum-extent="-20037508.34,-20037508.34,20037508.34,20037508.34">
+
+
+<Style name="railway" filter-mode="first" >
+  <Rule>
+    <Filter>([foo] = 'bar') and ([name].match('East.*'))</Filter>
+    <LineSymbolizer stroke="#008000" stroke-width="4" />
+  </Rule>
+</Style>
+<Layer name="railway"
+  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">
+    <StyleName>railway</StyleName>
+    <Datasource>
+       <Parameter name="file"><![CDATA[[absolute path]]]></Parameter>
+       <Parameter name="type"><![CDATA[shape]]></Parameter>
+    </Datasource>
+  </Layer>
+
+</Map>