Restore function to Show more button

There was a serious regression in go-gitea#21012 which broke the Show More
button on the diff page, and the show more button was also broken on the
file tree too.

This PR fixes this by resetting the pageData.diffFiles as the vue
watched value and reattachs a function to the show more button outside
of the file tree view.

Fix go-gitea#22380

Signed-off-by: Andrew Thornton <art27@cantab.net>

Author: zeripath

web_src/js/components/DiffFileTree.vue

@@ -29,6 +29,7 @@ export default {
   },
   computed: {
     fileTree() {
+      pageData.diffFileInfo.files = this.files;
       const result = [];
       for (const file of this.files) {
         // Split file into directories

web_src/js/features/repo-diff.js

@@ -119,25 +119,46 @@ function onShowMoreFiles() {
 
 export function doLoadMoreFiles(link, diffEnd, callback) {
   const url = `${link}?skip-to=${diffEnd}&file-only=true`;
+  loadMoreFiles(url, callback);
+}
+
+function loadMoreFiles(url, callback) {
+  const $target = $('a#diff-show-more-files');
+  if ($target.hasClass('disabled')) {
+    callback();
+    return;
+  }
+  $target.addClass('disabled');
   $.ajax({
     type: 'GET',
     url,
   }).done((resp) => {
     if (!resp) {
+      $target.removeClass('disabled');
       callback(resp);
       return;
     }
+    $('#diff-incomplete').replaceWith($(resp).find('#diff-file-boxes').children());
     // By simply rerunning the script we add the new data to our existing
     // pagedata object. this triggers vue and the filetree and filelist will
     // render the new elements.
     $('body').append($(resp).find('script#diff-data-script'));
+    onShowMoreFiles();
     callback(resp);
   }).fail(() => {
+    $target.removeClass('disabled');
     callback();
   });
 }
 
 export function initRepoDiffShowMore() {
+  $(document).on('click', 'a#diff-show-more-files', (e) => {
+    e.preventDefault();
+
+    const $target = $(e.target);
+    loadMoreFiles($target.data('href'), () => {});
+  });
+
   $(document).on('click', 'a.diff-show-more-button', (e) => {
     e.preventDefault();
     const $target = $(e.target);