Remove Column and Row properties from Form

Change-Id: I986ce001d40ff7ea4423e7a21d29e3fad3e2eabc

appinventor/appengine/src/com/google/appinventor/client/editor/simple/components/MockVisibleComponent.java

@@ -47,8 +47,8 @@ public abstract class MockVisibleComponent extends MockComponent {
   protected static final String PROPERTY_NAME_VISIBLE = "Visible";
   protected static final String PROPERTY_NAME_WIDTH = "Width";
   protected static final String PROPERTY_NAME_HEIGHT = "Height";
-  protected static final String PROPERTY_NAME_COLUMN = "Column";
-  protected static final String PROPERTY_NAME_ROW = "Row";
+  public static final String PROPERTY_NAME_COLUMN = "Column";
+  public static final String PROPERTY_NAME_ROW = "Row";
 
   // Note: the values below are duplicated in Component.java
   // If you change them here, change them there!

appinventor/appengine/src/com/google/appinventor/client/editor/youngandroid/YaFormEditor.java

@@ -25,6 +25,7 @@ import com.google.appinventor.client.editor.simple.components.FormChangeListener
 import com.google.appinventor.client.editor.simple.components.MockComponent;
 import com.google.appinventor.client.editor.simple.components.MockContainer;
 import com.google.appinventor.client.editor.simple.components.MockForm;
+import com.google.appinventor.client.editor.simple.components.MockVisibleComponent;
 import com.google.appinventor.client.editor.simple.components.utils.PropertiesUtil;
 import com.google.appinventor.client.editor.simple.palette.DropTargetProvider;
 import com.google.appinventor.client.editor.simple.palette.SimpleComponentDescriptor;
@@ -637,6 +638,16 @@ public final class YaFormEditor extends SimpleEditor implements FormChangeListen
     String componentName = properties.get("$Name").asString().getString();
     mockComponent.changeProperty("Name", componentName);
 
+    if (mockComponent instanceof MockForm) {
+      // A bug in an early version of multiselect resulted in Form gaining Row and Column
+      // properties, which are reserved for visible components that can appear in TableArrangements.
+      // Form doesn't have these properties, so we need to clean up the properties. The remove
+      // call here is idempotent--if the property is present, it is removed. If not present, the
+      // map remains unchanged.
+      properties.remove(MockVisibleComponent.PROPERTY_NAME_ROW);
+      properties.remove(MockVisibleComponent.PROPERTY_NAME_COLUMN);
+    }
+
     // Set component properties
     for (String name : properties.keySet()) {
       if (name.charAt(0) != '$') { // Ignore special properties (name, type and nested components)