Fix the "Reload with full diff" URL button

On the first load, the merge request tabs would be requested in JSON format to render
the HTML. This would cause the "Reload with full diff" button to create a link to diff.json.

Closes #2041

CHANGELOG

@@ -3,6 +3,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 v 7.14.0 (unreleased)
   - Fix full screen mode for snippet comments (Daniel Gerhardt)
   - Fix 404 error in files view after deleting the last file in a repository (Stan Hu)
+  - Fix the "Reload with full diff" URL button (Stan Hu)
   - Fix label read access for unauthenticated users (Daniel Gerhardt)
   - Fix access to disabled features for unauthenticated users (Daniel Gerhardt)
   - Fix OAuth provider bug where GitLab would not go return to the redirect_uri after sign-in (Stan Hu)

app/assets/javascripts/merge_request_tabs.js.coffee

@@ -49,12 +49,6 @@ class @MergeRequestTabs
     # Store the `location` object, allowing for easier stubbing in tests
     @_location = location
 
-    switch @opts.action
-      when 'commits'
-        @commitsLoaded = true
-      when 'diffs'
-        @diffsLoaded = true
-
     @bindEvents()
     @activateTab(@opts.action)
 
@@ -102,7 +96,7 @@ class @MergeRequestTabs
     action = 'notes' if action == 'show'
 
     # Remove a trailing '/commits' or '/diffs'
-    new_state = @_location.pathname.replace(/\/(commits|diffs)\/?$/, '')
+    new_state = @_location.pathname.replace(/\/(commits|diffs)(\.html)?\/?$/, '')
 
     # Append the new action if we're on a tab other than 'notes'
     unless action == 'notes'
@@ -133,7 +127,7 @@ class @MergeRequestTabs
     return if @diffsLoaded
 
     @_get
-      url: "#{source}.json"
+      url: "#{source}.json" + @_location.search
       success: (data) =>
         document.getElementById('diffs').innerHTML = data.html
         @diffsLoaded = true

app/views/projects/diffs/_warning.html.haml

@@ -3,7 +3,7 @@
     Too many changes to show.
     .pull-right
       - unless diff_hard_limit_enabled?
-        = link_to "Reload with full diff", url_for(params.merge(force_show_diff: true)), class: "btn btn-sm btn-warning"
+        = link_to "Reload with full diff", url_for(params.merge(force_show_diff: true, format: :html)), class: "btn btn-sm btn-warning"
 
       - if current_controller?(:commit) or current_controller?(:merge_requests)
         - if current_controller?(:commit)

app/views/projects/merge_requests/_show.html.haml

@@ -66,11 +66,9 @@
     #notes.notes.tab-pane.voting_notes
       = render "projects/merge_requests/discussion"
     #commits.commits.tab-pane
-      - if current_page?(action: 'commits')
-        = render "projects/merge_requests/show/commits"
+      - # This tab is always loaded via AJAX
     #diffs.diffs.tab-pane
-      - if current_page?(action: 'diffs')
-        = render "projects/merge_requests/show/diffs"
+      - # This tab is always loaded via AJAX
 
   .mr-loading-status
     = spinner

spec/javascripts/merge_request_tabs_spec.js.coffee

@@ -51,6 +51,12 @@ describe 'MergeRequestTabs', ->
       expect(@subject('notes')).toBe('/foo/bar/merge_requests/1')
       expect(@subject('commits')).toBe('/foo/bar/merge_requests/1/commits')
 
+    it 'changes from diffs.html', ->
+      @class._location = stubLocation(pathname: '/foo/bar/merge_requests/1/diffs.html')
+
+      expect(@subject('notes')).toBe('/foo/bar/merge_requests/1')
+      expect(@subject('commits')).toBe('/foo/bar/merge_requests/1/commits')
+
     it 'changes from notes', ->
       @class._location = stubLocation(pathname: '/foo/bar/merge_requests/1')