Ticket #35614: 35614.diff

src/wp-includes/capabilities.php

@@ -429 +429 @@
         case 'assign_term':
                 $term_id = $args[0];
                 $term = get_term( $term_id );
-                if ( ! $term || is_wp_error( $term ) ) {
+                if ( ! $term ) {
                         $caps[] = 'do_not_allow';
                         break;
                 }
 
+                if ( is_wp_error( $term ) ) {
+                        if ( 'ambiguous_term_id' === $term->get_error_code() ) {
+                                _split_shared_term( $term_id, /* $tt_id */ );
+                        }
+
+                        $caps[] = 'do_not_allow';
+                        break;
+                }
+
                 $tax = get_taxonomy( $term->taxonomy );
                 if ( ! $tax ) {
                         $caps[] = 'do_not_allow';