Changeset 8899

Timestamp:

05/30/2019 10:11:34 PM (6 years ago)

Author:

coffee2code

Message:

Handbook plugin: Prevent duplicate anchors when generating table of contents links from heading tags.

Previously, if text for a heading was used more than once in the page, the same anchor would be created for each heading, making the second (and subsequent) duplicates untargetable and the toc links would all point to the first instance.

Fixes #4406.

File:

• sites/trunk/wordpress.org/public_html/wp-content/plugins/handbook/inc/table-of-contents.php (modified) (5 diffs)

sites/trunk/wordpress.org/public_html/wp-content/plugins/handbook/inc/table-of-contents.php

@@ -89 +89 @@
             $toc .= "<$contents_header>" . esc_html( $this->args->header_text ) . "</$contents_header><ul class=\"items\">";
             $last_item = false;
+            $used_ids = [];
+
             foreach ( $items as $item ) {
                 if ( $last_item ) {
@@ -100 +102 @@
 
                 $last_item = $item[2];
-                $toc .= '<li><a href="#' . sanitize_title_with_dashes($item[3])  . '">' . $item[3]  . '</a>';
+
+                $id = sanitize_title_with_dashes( $item[3] );
+                // Append unique suffix if anchor ID isn't unique.
+                $count = 2;
+                $orig_id = $id;
+                while ( in_array( $id, $used_ids ) && $count < 50 ) {
+                    $id = $orig_id . '-' . $count;
+                    $count++;
+                }
+                $used_ids[] = $id;
+
+                $toc .= '<li><a href="#' . esc_attr( $id  ) . '">' . $item[3]  . '</a>';
             }
             $toc .= "</ul>\n</div>\n";
@@ -113 +126 @@
         $matches = array();
         $replacements = array();
+        $used_ids = array();
 
         foreach ( $items as $item ) {
@@ -119 +133 @@
             $id = sanitize_title_with_dashes($item[2]);
 
+            // Append unique suffix if anchor ID isn't unique.
+            $count = 2;
+            $orig_id = $id;
+            while ( in_array( $id, $used_ids ) && $count < 50 ) {
+                $id = $orig_id . '-' . $count;
+                $count++;
+            }
+            $used_ids[] = $id;
+        
             if ( ! $first ) {
                 $replacement .= '<p class="toc-jump"><a href="#top">' . __( 'Top &uarr;', 'wporg' ) . '</a></p>';
@@ -131 +154 @@
 
         if ( $replacements ) {
-            $content = str_replace( $matches, $replacements, $content );
+            if ( count( array_unique( $matches ) ) !== count( $matches ) ) {
+                foreach ( $matches as $i => $match ) {
+                    $content = preg_replace( '/' . preg_quote( $match, '/' ) . '/', $replacements[ $i ], $content, 1 );
+                }
+            } else {
+                $content = str_replace( $matches, $replacements, $content );
+            }
         }