FIX: Keep user in same context after login (#31314)

This fixes the destination of the auth process in the following
scenarios:

- when landing on a PM or a topic as an anonymous user and then loggin
in
- when landing on a public topic, hitting Reply or Like and then logging
in

app/assets/javascripts/discourse/app/components/modal/login.js

@@ -137,6 +137,8 @@ export default class Login extends Component {
           } else if (destinationUrl) {
             removeCookie("destination_url");
             window.location.assign(destinationUrl);
+          } else if (this.args.model.referrerUrl) {
+            window.location.assign(this.args.model.referrerUrl);
           } else {
             window.location.reload();
           }
@@ -288,6 +290,8 @@ export default class Login extends Component {
           removeCookie("destination_url");
 
           applyHiddenFormInputValue(destinationUrl, "redirect");
+        } else if (this.args.model.referrerUrl) {
+          applyHiddenFormInputValue(this.args.model.referrerUrl, "redirect");
         } else {
           applyHiddenFormInputValue(window.location.href, "redirect");
         }

app/assets/javascripts/discourse/app/controllers/login.js

@@ -160,6 +160,8 @@ export default class LoginPageController extends Controller {
           } else if (destinationUrl) {
             removeCookie("destination_url");
             window.location.assign(destinationUrl);
+          } else if (this.referrerUrl) {
+            window.location.assign(this.referrerUrl);
           } else {
             window.location.reload();
           }
@@ -337,6 +339,8 @@ export default class LoginPageController extends Controller {
           removeCookie("destination_url");
 
           applyHiddenFormInputValue(destinationUrl, "redirect");
+        } else if (this.referrerUrl) {
+          applyHiddenFormInputValue(this.referrerUrl, "redirect");
         } else {
           applyHiddenFormInputValue(window.location.href, "redirect");
         }

app/assets/javascripts/discourse/app/routes/application.js

@@ -298,6 +298,9 @@ export default class ApplicationRoute extends DiscourseRoute {
             showNotActivated: (props) => this.send("showNotActivated", props),
             showCreateAccount: (props) => this.send("showCreateAccount", props),
             canSignUp: this.controller.canSignUp,
+            referrerUrl: DiscourseURL.isInternal(document.referrer)
+              ? document.referrer
+              : null,
           },
         });
       }

app/assets/javascripts/discourse/app/routes/login.js

@@ -1,5 +1,6 @@
 import { next } from "@ember/runloop";
 import { service } from "@ember/service";
+import DiscourseURL from "discourse/lib/url";
 import { defaultHomepage } from "discourse/lib/utilities";
 import StaticPage from "discourse/models/static-page";
 import DiscourseRoute from "discourse/routes/discourse";
@@ -9,7 +10,11 @@ export default class LoginRoute extends DiscourseRoute {
   @service router;
   @service login;
 
-  beforeModel() {
+  beforeModel(transition) {
+    if (transition.from) {
+      this.internalReferrer = this.router.urlFor(transition.from.name);
+    }
+
     if (this.siteSettings.login_required) {
       if (
         this.login.isOnlyOneExternalLoginMethod &&
@@ -49,6 +54,10 @@ export default class LoginRoute extends DiscourseRoute {
     controller.set("flashType", "");
     controller.set("flash", "");
 
+    if (this.internalReferrer || DiscourseURL.isInternal(document.referrer)) {
+      controller.set("referrerUrl", this.internalReferrer || document.referrer);
+    }
+
     if (this.siteSettings.login_required) {
       controller.set("showLogin", false);
     }

spec/system/login_spec.rb

@@ -88,9 +88,6 @@ shared_examples "login scenarios" do |login_page_object|
 
       # TODO: prefill username when fullpage
       if find("#username-or-email").value.blank?
-        if page.has_css?("html.mobile-view", wait: 0)
-          expect(page).to have_no_css(".d-modal.is-animating")
-        end
         find("#username-or-email").fill_in(with: user.username)
       end
 
@@ -126,6 +123,60 @@ shared_examples "login scenarios" do |login_page_object|
       login_form.fill(username: "john", password: "supersecurepassword").click_login
       expect(page).to have_css(".header-dropdown-toggle.current-user")
     end
+
+    it "redirects to a PM after login" do
+      EmailToken.confirm(Fabricate(:email_token, user: user).token)
+
+      group = Fabricate(:group, publish_read_state: true)
+      Fabricate(:group_user, group: group, user: user)
+      pm = Fabricate(:private_message_topic, allowed_groups: [group])
+      Fabricate(:post, topic: pm, user: user, reads: 2, created_at: 1.day.ago)
+      Fabricate(:group_private_message_topic, user: user, recipient_group: group)
+
+      visit "/t/#{pm.id}"
+      find(".login-welcome .login-button").click
+      login_form.fill(username: "john", password: "supersecurepassword").click_login
+
+      expect(page).to have_css(".header-dropdown-toggle.current-user")
+      expect(page).to have_css("#topic-title")
+      expect(page).to have_css(".private_message")
+    end
+  end
+
+  context "when login is not required" do
+    before { SiteSetting.login_required = false }
+
+    it "redirects to a PM after authentication" do
+      EmailToken.confirm(Fabricate(:email_token, user: user).token)
+      group = Fabricate(:group, publish_read_state: true)
+      Fabricate(:group_user, group: group, user: user)
+      pm = Fabricate(:private_message_topic, allowed_groups: [group])
+      Fabricate(:post, topic: pm, user: user, reads: 2, created_at: 1.day.ago)
+      Fabricate(:group_private_message_topic, user: user, recipient_group: group)
+
+      visit "/t/#{pm.id}"
+      find(".btn.login-button").click
+
+      login_form.fill(username: "john", password: "supersecurepassword").click_login
+      expect(page).to have_css(".header-dropdown-toggle.current-user")
+
+      expect(page).to have_css("#topic-title")
+      expect(page).to have_css(".private_message")
+    end
+
+    it "redirects to a public topic when hitting Reply then logging in" do
+      EmailToken.confirm(Fabricate(:email_token, user: user).token)
+      topic = Fabricate(:topic)
+      Fabricate(:post, topic: topic, created_at: 1.day.ago)
+
+      visit "/t/#{topic.id}"
+      find(".topic-footer-main-buttons .btn-primary").click
+
+      login_form.fill(username: "john", password: "supersecurepassword").click_login
+      expect(page).to have_css(".header-dropdown-toggle.current-user")
+
+      expect(page).to have_css("#topic-title")
+    end
   end
 
   context "with two-factor authentication" do