strip_shortcodes Chokes On Empty Shortcodes

[MathSmath]

It appears the regex for strip_shortcodes doesn't recognize empty shortcodes. For example, a caption shortcode like this would only have the opening shortcode tag stripped:

[caption id="attachment_3360" width="288" caption="Some caption"][/caption]

The closing caption tag remains in the resulting string.

I realize this is a fringe case (why would you have an empty caption?), but it popped up for me when working with a popular plugin that attempts to generate an excerpt by doing the following:

$content = strip_tags($content);
$content = strip_shortcodes($content);

Seems harmless--but if a caption contains only an image tag, the strip_tags removes it, and the strip_shortcodes chokes on the now-empty shortcode. Or even worse, if you have a second caption shortcode in the content, it strips EVERYTHING between the first opening caption tag and the second closing caption tag.

And I have to imagine there are some custom shortcodes that may be legitimately empty for some reason. I dunno.

To reproduce:

$content = '[caption][/caption]

Lorem ipsum dolor sit amet, consectetur adipiscing elit.

[caption][/caption]';

$content = strip_shortcodes($content);

echo $content;