Ticket #45493: 45493.3.diff

src/js/_enqueues/vendor/tinymce/plugins/wpeditimage/plugin.js

@@ -221 +221 @@
                                 // Convert remaining line breaks to <br>.
                                 caption = caption.replace( /\s*\n\s*/g, '<br />' );
 
+                                // Convert square brackets to HTML entities in the shortcode.
+                                caption = caption.replace( /\[/g, '&#91;' ).replace( /\]/g, '&#93;' );
+
                                 return '[caption id="' + id + '" align="' + align + '" width="' + width + '"' + classes + ']' + c + ' ' + caption + '[/caption]';
                         });