fix for #681 - Make sure markers layer always draws on the first moveTo(), regardless of the value of 'zoomChanged'.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@3098 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Markers.js

@@ -22,6 +22,15 @@ OpenLayers.Layer.Markers.prototype =
     * @type Array(OpenLayers.Marker) */
     markers: null,
 
+
+    /** internal state of drawing. This is a workaround for the fact
+     *  that the map does not call moveTo with a zoomChanged when the
+     *  map is first starting up. This lets us catch the case where we
+     *  have *never* drawn the layer, and draw it even if the zoom hasn't
+     *  changed. 
+     * @type Boolean */
+    drawn: false,
+    
     /**
     * @constructor
     *
@@ -51,8 +60,9 @@ OpenLayers.Layer.Markers.prototype =
     moveTo:function(bounds, zoomChanged, dragging) {
         OpenLayers.Layer.prototype.moveTo.apply(this, arguments);
 
-        if (zoomChanged) {
+        if (zoomChanged || !this.drawn) {
             this.redraw();
+            this.drawn = true;
         }
     },