Widget will not be shown in case of its id includes upper characters

[kamiyeye]

Pre-requisite:

A widget with its id/id_base includes at least one upper character

Repro Steps:

1. Access the back-end page 'Appearance->Widget'

2. Drag the widget to a sidebar

3. Simply refresh the page

Expected Results:

The widget is shown on that sidebar

Actual Results:

The widget isn't shown on that sidebar

Cause:

Before a widget is registered ,the field 'id' is lowered, say:

-- line 557,function wp_register_sidebar_widget,file widgets.php---

  $id = strtolower($id);

But 'id' stored in new WP_Widget class is not lowered:

-- line 90, function __construct, file widgets.php-----------------

$this->id_base = empty($id_base) ? preg_replace( '/(wp_)?widget_/', '', strtolower(get_class($this)) ) : $id_base;

I gathered from these that why the widget isn't shown is because no widgets with such an id(has some upper characters) found in the registered widgets(all ids are lowered), am i right?

P.S.

It tooks me several hours on this issue, i reviewed my widget codes again and again, every time, couldn't found any fault.I were almost mad before i caught the damned issue. Now, it's yours.

[Denis-de-Bernardy]

either of the above two approaches should work. but the second one might be preferred, if the strtolower() was anything useful.

[azaozz]

(In [11308]) Lowercase widgets $id_base, props Denis-de-Bernardy, fixes #9797

[azaozz]

Think it has to be set to lower case since allowing mixed/upper case in wp_register_sidebar_widget() could break older widgets.