Woocommerce Gallery Image Caption: Use “caption” — not “alt tag”. Keep alt tag as is

Phew!

Here is the code for functions.php.

add_filter( 'woocommerce_single_product_image_thumbnail_html', 'change_alt_to_caption_gallery_images', 10, 2 );

function change_alt_to_caption_gallery_images ( $wc_get_gallery_image_html, $image_id ){

    $caption = get_post_field( 'post_excerpt', $image_id ); 

    if ( !empty($caption) && !empty($wc_get_gallery_image_html) ) {

        $caption = str_replace( '"', "''", $caption );
        $caption_repl="data-caption="" . $caption . '"';
        $wc_get_gallery_image_html = preg_replace( '/data-thumb-alt="[^"]+"/', $caption_repl, $wc_get_gallery_image_html );

    }
    return $wc_get_gallery_image_html;
}