[Admin Emails] The frontend should use the v3 API for now

app/assets/javascripts/admin_email_select.js

@@ -17,7 +17,8 @@
               group_result = Api.groups(query.term, {}, function(groups) {
                 return groups;
               });
-              project_result = Api.projects(query.term, 'id', function(projects) {
+              // Should be replaced with "Api.projects" when API v4 is frozen (9.1)
+              project_result = Api.allProjects(query.term, 'id', function(projects) {
                 return projects;
               });
               return $.when(project_result, group_result).done(function(projects, groups) {

app/assets/javascripts/api.js

@@ -7,6 +7,7 @@
     namespacesPath: "/api/:version/namespaces.json",
     groupProjectsPath: "/api/:version/groups/:id/projects.json",
     projectsPath: "/api/:version/projects.json?simple=true",
+    allProjectsPath: "/api/:version/projects/all.json?simple=true", // Deprecated. Valid for API v3 only.
     labelsPath: "/:namespace_path/:project_path/labels",
     licensePath: "/api/:version/templates/licenses/:key",
     gitignorePath: "/api/:version/templates/gitignores/:key",
@@ -67,6 +68,24 @@
         return callback(projects);
       });
     },
+    // Deprecated and should be deleted for 9.1
+    // Also the 'Api.allProjectsPath' should be deleted as well.
+    // Basically, the whole commit that adds this comment should be reverted when API v4 is frozen (9.1)
+    // Details here: https://gitlab.com/gitlab-org/gitlab-ce/issues/28853#note_24410695
+    allProjects: function(query, order, callback) {
+      var url = Api.buildUrl(Api.allProjectsPath);
+      return $.ajax({
+        url: url,
+        data: {
+          search: query,
+          order_by: order,
+          per_page: 20
+        },
+        dataType: "json"
+      }).done(function(projects) {
+        return callback(projects);
+      });
+    },
     newLabel: function(namespace_path, project_path, data, callback) {
       var url = Api.buildUrl(Api.labelsPath)
         .replace(':namespace_path', namespace_path)