Merge pull request #87 from nextcloud/gridBug

check if correct adapter is used

src/com/owncloud/android/ui/fragment/ExtendedListFragment.java

@@ -427,7 +427,7 @@ public class ExtendedListFragment extends Fragment
      */
     protected void setFooterEnabled(boolean enabled) {
         if (enabled) {
-            if (mGridView.getFooterViewCount() == 0) {
+            if (mGridView.getFooterViewCount() == 0 && mGridView.isCorrectAdapter()) {
                 if (mGridFooterView.getParent() != null ) {
                     ((ViewGroup) mGridFooterView.getParent()).removeView(mGridFooterView);
                 }

src/third_parties/in/srain/cube/GridViewWithHeaderAndFooter.java

@@ -412,6 +412,10 @@ public class GridViewWithHeaderAndFooter extends GridView {
         }
     }
 
+    public boolean isCorrectAdapter(){
+        return getAdapter() == null || getAdapter() instanceof HeaderViewGridAdapter;
+    }
+
     /**
      * ListAdapter used when a HeaderGridView has header views. This ListAdapter
      * wraps another one and also keeps track of the header views and their