9 files changed, 66 insertions, 22 deletions

diff --git a/app/assets/javascripts/pages/projects/blob/show/index.js b/app/assets/javascripts/pages/projects/blob/show/index.js
index a0f391c912b..02fcc6ea940 100644
--- a/app/assets/javascripts/pages/projects/blob/show/index.js
+++ b/app/assets/javascripts/pages/projects/blob/show/index.js
@@ -15,7 +15,7 @@ import '~/sourcegraph/load';
 import createStore from '~/code_navigation/store';
 import { generateRefDestinationPath } from '~/repository/utils/ref_switcher_utils';
 import RefSelector from '~/ref/components/ref_selector.vue';
-import { visitUrl } from '~/lib/utils/url_utility';
+import { joinPaths, visitUrl } from '~/lib/utils/url_utility';
 
 Vue.use(Vuex);
 Vue.use(VueApollo);
@@ -34,7 +34,7 @@ const initRefSwitcher = () => {
 
   if (!refSwitcherEl) return false;
 
-  const { projectId, projectRootPath, ref } = refSwitcherEl.dataset;
+  const { projectId, projectRootPath, ref, refType } = refSwitcherEl.dataset;
 
   return new Vue({
     el: refSwitcherEl,
@@ -42,7 +42,8 @@ const initRefSwitcher = () => {
       return createElement(RefSelector, {
         props: {
           projectId,
-          value: ref,
+          value: refType ? joinPaths('refs', refType, ref) : ref,
+          useSymbolicRefNames: true,
         },
         on: {
           input(selectedRef) {
diff --git a/app/assets/javascripts/repository/index.js b/app/assets/javascripts/repository/index.js
index 6cedc606a37..0db9dcb43df 100644
--- a/app/assets/javascripts/repository/index.js
+++ b/app/assets/javascripts/repository/index.js
@@ -2,7 +2,7 @@ import { GlButton } from '@gitlab/ui';
 import Vue from 'vue';
 import Vuex from 'vuex';
 import { parseBoolean } from '~/lib/utils/common_utils';
-import { escapeFileUrl, visitUrl } from '~/lib/utils/url_utility';
+import { joinPaths, escapeFileUrl, visitUrl } from '~/lib/utils/url_utility';
 import { __ } from '~/locale';
 import initWebIdeLink from '~/pages/projects/shared/web_ide_link';
 import PerformancePlugin from '~/performance/vue_performance_plugin';
@@ -128,7 +128,7 @@ export default function setupVueRepositoryList() {
 
     if (!refSwitcherEl) return false;
 
-    const { projectId, projectRootPath } = refSwitcherEl.dataset;
+    const { projectId, projectRootPath, refType } = refSwitcherEl.dataset;
 
     return new Vue({
       el: refSwitcherEl,
@@ -136,7 +136,8 @@ export default function setupVueRepositoryList() {
         return createElement(RefSelector, {
           props: {
             projectId,
-            value: ref,
+            value: refType ? joinPaths('refs', refType, ref) : ref,
+            useSymbolicRefNames: true,
           },
           on: {
             input(selectedRef) {
diff --git a/app/assets/javascripts/repository/utils/ref_switcher_utils.js b/app/assets/javascripts/repository/utils/ref_switcher_utils.js
index c62f7f709c4..bcad4a2c822 100644
--- a/app/assets/javascripts/repository/utils/ref_switcher_utils.js
+++ b/app/assets/javascripts/repository/utils/ref_switcher_utils.js
@@ -16,22 +16,29 @@ const getNamespaceTargetRegex = (ref) => new RegExp(`(/-/(blob|tree))/${ref}/(.*
  * @param {string} selectedRef - The selected ref from the ref dropdown.
  */
 export function generateRefDestinationPath(projectRootPath, ref, selectedRef) {
-  const currentPath = window.location.pathname;
-  const encodedHash = '%23';
+  const url = new URL(window.location.href);
+  const currentPath = url.pathname;
+  let refType = null;
   let namespace = '/-/tree';
   let target;
+  let actualRef = selectedRef;
+
+  const matches = selectedRef.match(/^refs\/(heads|tags)\/(.+)/);
+  if (matches) {
+    [, refType, actualRef] = matches;
+  }
+  if (refType) {
+    url.searchParams.set('ref_type', refType);
+  } else {
+    url.searchParams.delete('ref_type');
+  }
+
   const NAMESPACE_TARGET_REGEX = getNamespaceTargetRegex(ref);
   const match = NAMESPACE_TARGET_REGEX.exec(currentPath);
   if (match) {
     [, namespace, , target] = match;
   }
+  url.pathname = joinPaths(projectRootPath, namespace, actualRef, target);
 
-  const destinationPath = joinPaths(
-    projectRootPath,
-    namespace,
-    encodeURI(selectedRef).replace(/#/g, encodedHash),
-    target,
-  );
-
-  return `${destinationPath}${window.location.hash}`;
+  return url.toString();
 }
diff --git a/app/controllers/concerns/confirm_email_warning.rb b/app/controllers/concerns/confirm_email_warning.rb
index 8b7371cbc17..2efea461a35 100644
--- a/app/controllers/concerns/confirm_email_warning.rb
+++ b/app/controllers/concerns/confirm_email_warning.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 module ConfirmEmailWarning
+  include Gitlab::Utils::StrongMemoize
   extend ActiveSupport::Concern
 
   included do
@@ -17,11 +18,9 @@ module ConfirmEmailWarning
     return unless current_user
     return if current_user.confirmed?
 
-    email = current_user.unconfirmed_email || current_user.email
-
     flash.now[:warning] = format(
       confirm_warning_message,
-      email: email,
+      email: email_to_display,
       resend_link: view_context.link_to(_('Resend it'), user_confirmation_path(user: { email: email }), method: :post),
       update_link: view_context.link_to(_('Update it'), profile_path)
     ).html_safe
@@ -29,7 +28,16 @@ module ConfirmEmailWarning
 
   private
 
+  def email
+    current_user.unconfirmed_email || current_user.email
+  end
+  strong_memoize_attr :email
+
   def confirm_warning_message
     _("Please check your email (%{email}) to verify that you own this address and unlock the power of CI/CD. Didn't receive it? %{resend_link}. Wrong email address? %{update_link}.")
   end
+
+  def email_to_display
+    html_escape(email)
+  end
 end
diff --git a/app/controllers/projects/blob_controller.rb b/app/controllers/projects/blob_controller.rb
index 3413aeb6f8a..2d0c4a0a6c1 100644
--- a/app/controllers/projects/blob_controller.rb
+++ b/app/controllers/projects/blob_controller.rb
@@ -31,6 +31,7 @@ class Projects::BlobController < Projects::ApplicationController
   before_action :authorize_edit_tree!, only: [:new, :create, :update, :destroy]
 
   before_action :commit, except: [:new, :create]
+  before_action :check_for_ambiguous_ref, only: [:show]
   before_action :blob, except: [:new, :create]
   before_action :require_branch_head, only: [:edit, :update]
   before_action :editor_variables, except: [:show, :preview, :diff]
@@ -157,6 +158,15 @@ class Projects::BlobController < Projects::ApplicationController
     end
   end
 
+  def check_for_ambiguous_ref
+    @ref_type = ref_type
+
+    if @ref_type == ExtractsRef::BRANCH_REF_TYPE && ambiguous_ref?(@project, @ref)
+      branch = @project.repository.find_branch(@ref)
+      redirect_to project_blob_path(@project, File.join(branch.target, @path))
+    end
+  end
+
   def commit
     @commit ||= @repository.commit(@ref)
 
diff --git a/app/controllers/projects/tree_controller.rb b/app/controllers/projects/tree_controller.rb
index ba18a2e0dce..a8b54933487 100644
--- a/app/controllers/projects/tree_controller.rb
+++ b/app/controllers/projects/tree_controller.rb
@@ -28,6 +28,15 @@ class Projects::TreeController < Projects::ApplicationController
   def show
     return render_404 unless @commit
 
+    @ref_type = ref_type
+    if @ref_type == BRANCH_REF_TYPE && ambiguous_ref?(@project, @ref)
+      branch = @project.repository.find_branch(@ref)
+      if branch
+        redirect_to project_tree_path(@project, branch.target)
+        return
+      end
+    end
+
     if tree.entries.empty?
       if @repository.blob_at(@commit.id, @path)
         redirect_to project_blob_path(@project, File.join(@ref, @path))
diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index f18055f80b7..c12caecdc23 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -173,11 +173,19 @@ class ProjectsController < Projects::ApplicationController
       flash.now[:alert] = _("Project '%{project_name}' queued for deletion.") % { project_name: @project.name }
     end
 
+    if ambiguous_ref?(@project, @ref)
+      branch = @project.repository.find_branch(@ref)
+
+      # The files view would render a ref other than the default branch
+      # This redirect can be removed once the view is fixed
+      redirect_to(project_tree_path(@project, branch.target), alert: _("The default branch of this project clashes with another ref"))
+      return
+    end
+
     respond_to do |format|
       format.html do
         @notification_setting = current_user.notification_settings_for(@project) if current_user
         @project = @project.present(current_user: current_user)
-
         render_landing_page
       end
 
diff --git a/app/views/projects/blob/_breadcrumb.html.haml b/app/views/projects/blob/_breadcrumb.html.haml
index e77367a7b42..79b13dc861a 100644
--- a/app/views/projects/blob/_breadcrumb.html.haml
+++ b/app/views/projects/blob/_breadcrumb.html.haml
@@ -2,7 +2,7 @@
 .nav-block
   .tree-ref-container
     .tree-ref-holder
-      #js-tree-ref-switcher{ data: { project_id: @project.id, project_root_path: project_path(@project), ref: current_ref } }
+      #js-tree-ref-switcher{ data: { project_id: @project.id, project_root_path: project_path(@project), ref: current_ref, ref_type: @ref_type.to_s } }
 
     %ul.breadcrumb.repo-breadcrumb
       %li.breadcrumb-item
diff --git a/app/views/projects/tree/_tree_header.html.haml b/app/views/projects/tree/_tree_header.html.haml
index 6cd3c584f2a..d494d9cc36d 100644
--- a/app/views/projects/tree/_tree_header.html.haml
+++ b/app/views/projects/tree/_tree_header.html.haml
@@ -2,7 +2,7 @@
 
 .tree-ref-container.gl-display-flex.gl-flex-wrap.gl-gap-2.mb-2.mb-md-0
   .tree-ref-holder.gl-max-w-26
-    #js-tree-ref-switcher{ data: { project_id: @project.id, project_root_path: project_path(@project) } }
+    #js-tree-ref-switcher{ data: { project_id: @project.id, ref_type: @ref_type.to_s, project_root_path: project_path(@project) } }
 
   #js-repo-breadcrumb{ data: breadcrumb_data_attributes }