[BugFix] Fix selectFeatures is null exception when layer is destroyed. Since you can listen only to preremovelayer to handle removing layer with SelectFeature. But preremovelayer is triggered after selectFeatures is set to null.

lib/OpenLayers/Control/SelectFeature.js

@@ -305,6 +305,7 @@ OpenLayers.Control.SelectFeature = OpenLayers.Class(OpenLayers.Control, {
         for(l=0; l<layers.length; ++l) {
             layer = layers[l];
             numExcept = 0;
+			if(layer.selectedFeatures != null) {
                 while(layer.selectedFeatures.length > numExcept) {
                     feature = layer.selectedFeatures[numExcept];
                     if(!options || options.except != feature) {
@@ -314,6 +315,7 @@ OpenLayers.Control.SelectFeature = OpenLayers.Class(OpenLayers.Control, {
                     }
                 }
 			}
+        }
     },
 
     /**