Merge pull request #7543 from ahocevar/interiorpoint-donut

Donut polygon labels do not get a chance to get rendered

src/ol/geom/flat/interiorpoint.js

@@ -24,7 +24,8 @@ ol.geom.flat.interiorpoint.linearRings = function(flatCoordinates, offset,
   /** @type {Array.<number>} */
   var intersections = [];
   // Calculate intersections with the horizontal line
-  var end = ends[0];
+  for (var r = 0, rr = ends.length; r < rr; ++r) {
+    var end = ends[r];
     x1 = flatCoordinates[end - stride];
     y1 = flatCoordinates[end - stride + 1];
     for (i = offset; i < end; i += stride) {
@@ -37,6 +38,7 @@ ol.geom.flat.interiorpoint.linearRings = function(flatCoordinates, offset,
       x1 = x2;
       y1 = y2;
     }
+  }
   // Find the longest segment of the horizontal line that has its center point
   // inside the linear ring.
   var pointX = NaN;

test/spec/ol/geom/polygon.test.js

@@ -550,6 +550,17 @@ describe('ol.geom.Polygon', function() {
       expect(interiorPoint.layout).to.be('XYM');
       expect(interiorPoint.getCoordinates()).to.eql([0.5, 0.5, 1]);
     });
+
+    it('returns XYM point for donut polygons', function() {
+      var geom = new ol.geom.Polygon([
+        [[0.5, 0.5], [0.5, 2.5], [2.5, 2.5], [2.5, 0.5], [0.5, 0.5]],
+        [[1, 1], [2, 1], [2, 2], [1, 2], [1, 1]]
+      ]);
+      var interiorPoint = geom.getInteriorPoint();
+      expect(interiorPoint.getType()).to.be('Point');
+      expect(interiorPoint.layout).to.be('XYM');
+      expect(interiorPoint.getCoordinates()).to.eql([0.75, 1.5, 0.5]);
+    });
   });
 
   describe('ol.geom.Polygon.fromExtent', function() {