Fix for re-entrant area calculation.

d3.js

@@ -6301,9 +6301,9 @@
       }
     }
     path.area = function(object) {
-      d3_geo_areaSum = 0;
+      d3_geo_pathAreaSum = 0;
       d3.geo.stream(object, projection.stream(d3_geo_pathArea));
-      return d3_geo_areaSum;
+      return d3_geo_pathAreaSum;
     };
     path.centroid = function(object) {
       d3_geo_centroidX = d3_geo_centroidY = d3_geo_centroidZ = 0;
@@ -6401,7 +6401,7 @@
     }
     return stream;
   }
-  var d3_geo_pathAreaPolygon, d3_geo_pathArea = {
+  var d3_geo_pathAreaSum, d3_geo_pathAreaPolygon, d3_geo_pathArea = {
     point: d3_noop,
     lineStart: d3_noop,
     lineEnd: d3_noop,
@@ -6411,7 +6411,7 @@
     },
     polygonEnd: function() {
       d3_geo_pathArea.lineStart = d3_geo_pathArea.lineEnd = d3_geo_pathArea.point = d3_noop;
-      d3_geo_areaSum += Math.abs(d3_geo_pathAreaPolygon / 2);
+      d3_geo_pathAreaSum += Math.abs(d3_geo_pathAreaPolygon / 2);
     }
   };
   function d3_geo_pathAreaRingStart() {

src/geo/path-area.js

@@ -1,6 +1,6 @@
 // TODO Unify this code with d3.geom.polygon area?
 
-var d3_geo_pathAreaPolygon, d3_geo_pathArea = {
+var d3_geo_pathAreaSum, d3_geo_pathAreaPolygon, d3_geo_pathArea = {
   point: d3_noop,
   lineStart: d3_noop,
   lineEnd: d3_noop,
@@ -12,7 +12,7 @@ var d3_geo_pathAreaPolygon, d3_geo_pathArea = {
   },
   polygonEnd: function() {
     d3_geo_pathArea.lineStart = d3_geo_pathArea.lineEnd = d3_geo_pathArea.point = d3_noop;
-    d3_geo_areaSum += Math.abs(d3_geo_pathAreaPolygon / 2);
+    d3_geo_pathAreaSum += Math.abs(d3_geo_pathAreaPolygon / 2);
   }
 };
 

src/geo/path.js

@@ -21,9 +21,9 @@ d3.geo.path = function() {
   }
 
   path.area = function(object) {
-    d3_geo_areaSum = 0;
+    d3_geo_pathAreaSum = 0;
     d3.geo.stream(object, projection.stream(d3_geo_pathArea));
-    return d3_geo_areaSum;
+    return d3_geo_pathAreaSum;
   };
 
   path.centroid = function(object) {