Normalise access widget_title in WP_Widget_Media

[Bsop]

It seems that in most default widgets, the filter widget_title is always available, even if the user did not provide a title. In the abstract class WP_Widget_Media however, this is not the case, the apply_filters function will only be called if a title property exists in $instance. This is of course impractical when one wants to apply a hook callback to all default widget titles.

[Bsop]

patch

[Bsop]

actually test for filtered title

[westonruter]

Good catch.

[SergeyBiryukov]

In 41866:

Widgets: In WP_Widget_Media, apply widget_title filter regardless of whether the title is empty, same as other widgets do.

Props Bsop.
Fixes #42226.

[SergeyBiryukov]

In 41867:

Widgets: Move empty title checks out of the apply_filters( 'widget_title' ) calls for clarity.

See #42226.