Ticket #8256: media_img_caption_shortcode_no_alt.diff

wp-includes/media.php

@@ -568 +568 @@
  * The supported attributes for the shortcode are 'id', 'align', 'width', and
  * 'caption'.
  *
+ * If the image's alternative text is identical to the caption text, the alt
+ * text will be removed (as alt="") unless you pass TRUE via the
+ * 'wp_img_caption_print_duplicate_alt' filter hook
+ *
  * @since 2.6.0
  *
  * @param array $attr Attributes attributed to the shortcode.
  * @param string $content Optional. Shortcode content.
+ * @uses apply_filters() Calls 'img_caption_shortcode' filter
+ * @uses apply_filters() Calls 'wp_img_caption_print_duplicate_alt' filter
  * @return string
  */
 function img_caption_shortcode($attr, $content = null) {
@@ -593 +599 @@
 
         if ( $id ) $id = 'id="' . esc_attr($id) . '" ';
 
+        if ( ! apply_filters( 'wp_img_caption_print_duplicate_alt', false ) ) {
+                // alt text is removed if identical to printed caption
+                $content = str_replace( sprintf( 'alt="%s"', esc_attr($caption) )
+                        , 'alt=""', $content );
+        }
+
         return '<div ' . $id . 'class="wp-caption ' . esc_attr($align) . '" style="width: ' . (10 + (int) $width) . 'px">'
         . do_shortcode( $content ) . '<p class="wp-caption-text">' . $caption . '</p></div>';
 }