Bug 96284 [Properties] Clicking OK on Properties page of plugin.xml gives unexpected "Conflict in Encoding"
N20050523-0010 - open the Properties dialog for a plugin.xml - click OK => Error message dialog "Conflict in Encoding": "null conflicts with the encoding defined in the content type (UTF-8). Do you wish to set it anyways?" with buttons "Yes" and "No". Since I have not changed teh encoding, I don't expect that dialog.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/ResourceEncodingFieldEditor.java
protected Composite createEncodingGroup(Composite parent, int numColumns) {
        Composite group = super.createEncodingGroup(parent, numColumns);
		String byteOrderLabel = IDEEncoding.getByteOrderMarkLabel(getContentDescription());
		if (byteOrderLabel != null) {
			Label label = new Label(group, SWT.NONE);
			label.setText(NLS.bind(IDEWorkbenchMessages.WorkbenchPreference_encoding_encodingMessage, byteOrderLabel));
			GridData layoutData = new GridData();
			layoutData.horizontalSpan = numColumns + 1;
			label.setLayoutData(layoutData);
		}
		return group;
	}
	/**
	 * Returns the content description of the resource if it is 
	 * a file and it has a content description.
     * 
	 * @return the content description or <code>null</code> if resource is
	 *   not an <code>IFile</code> or it does not have a description
	 */
	private IContentDescription getContentDescription() {
		try {
			if (resource instanceof IFile)
				return (((IFile) resource).getContentDescription());
		} catch (CoreException exception) {
			
		}
		return null;
	}
}