From 3387c8787c74556ed459f683fc65c4a2e93d93f7 Mon Sep 17 00:00:00 2001
From: Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
Date: Mon, 2 Dec 2019 11:01:20 -0300
Subject: [PATCH] unlockDialog: Create auth prompt on demand

AuthPrompt is the set of actors that contain the user avatar,
the username, and the password entry. With the removal of the
screen shield, the unlock dialog (be it UnlockDialog or the
LoginDialog) is always created, and in the case of UnlockDialog,
so is the auth prompt.

This is problematic, though, since for passwordless accounts,
the simple act of creating AuthPrompt authenticates the user,
and lifts the lock screen.

Create the AuthPrompt on deman in UnlockDialog.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/872
---
 js/ui/unlockDialog.js | 82 +++++++++++++++++++++++++++++--------------
 1 file changed, 55 insertions(+), 27 deletions(-)

diff --git a/js/ui/unlockDialog.js b/js/ui/unlockDialog.js
index 05a62ffb8..3fff8c401 100644
--- a/js/ui/unlockDialog.js
+++ b/js/ui/unlockDialog.js
@@ -445,34 +445,8 @@ var UnlockDialog = GObject.registerClass({
         stack.add_child(this._clock);
         this._showClock();
 
-        this._authPrompt = new AuthPrompt.AuthPrompt(new Gdm.Client(), AuthPrompt.AuthPromptMode.UNLOCK_ONLY);
-        this._authPrompt.connect('failed', this._fail.bind(this));
-        this._authPrompt.connect('cancelled', this._fail.bind(this));
-        this._authPrompt.connect('reset', this._onReset.bind(this));
-        this._authPrompt.setPasswordChar('\u25cf');
-        this._authPrompt.nextButton.label = _("Unlock");
-
-        this._promptBox.add_child(this._authPrompt);
-
         this.allowCancel = false;
 
-        let screenSaverSettings = new Gio.Settings({ schema_id: 'org.gnome.desktop.screensaver' });
-        if (screenSaverSettings.get_boolean('user-switch-enabled')) {
-            let otherUserLabel = new St.Label({ text: _("Log in as another user"),
-                                                style_class: 'login-dialog-not-listed-label' });
-            this._otherUserButton = new St.Button({ style_class: 'login-dialog-not-listed-button',
-                                                    can_focus: true,
-                                                    child: otherUserLabel,
-                                                    reactive: true });
-            this._otherUserButton.connect('clicked', this._otherUserClicked.bind(this));
-            this._promptBox.add_child(this._otherUserButton);
-        } else {
-            this._otherUserButton = null;
-        }
-
-        this._authPrompt.reset();
-        this._updateSensitivity(true);
-
         Main.ctrlAltTabManager.addGroup(this, _("Unlock Window"), 'dialog-password-symbolic');
 
         // Notifications
@@ -554,6 +528,53 @@ var UnlockDialog = GObject.registerClass({
             this._createBackground(i);
     }
 
+    _ensureAuthPrompt() {
+        if (this._authPrompt)
+            return;
+
+        this._authPrompt = new AuthPrompt.AuthPrompt(new Gdm.Client(), AuthPrompt.AuthPromptMode.UNLOCK_ONLY);
+        this._authPrompt.connect('failed', this._fail.bind(this));
+        this._authPrompt.connect('cancelled', this._fail.bind(this));
+        this._authPrompt.connect('reset', this._onReset.bind(this));
+        this._authPrompt.setPasswordChar('\u25cf');
+        this._authPrompt.nextButton.label = _("Unlock");
+
+        this._promptBox.add_child(this._authPrompt);
+
+        let screenSaverSettings = new Gio.Settings({ schema_id: 'org.gnome.desktop.screensaver' });
+        if (screenSaverSettings.get_boolean('user-switch-enabled')) {
+            let otherUserLabel = new St.Label({
+                text: _("Log in as another user"),
+                style_class: 'login-dialog-not-listed-label',
+            });
+            this._otherUserButton = new St.Button({
+                style_class: 'login-dialog-not-listed-button',
+                can_focus: true,
+                child: otherUserLabel,
+                reactive: true,
+            });
+            this._otherUserButton.connect('clicked', this._otherUserClicked.bind(this));
+            this._promptBox.add_child(this._otherUserButton);
+        } else {
+            this._otherUserButton = null;
+        }
+
+        this._authPrompt.reset();
+        this._updateSensitivity(true);
+    }
+
+    _maybeDestroyAuthPrompt() {
+        this.grab_key_focus();
+
+        if (this._authPrompt) {
+            this._authPrompt.destroy();
+            this._authPrompt = null;
+
+            this._otherUserButton.destroy();
+            this._otherUserButton = null;
+        }
+    }
+
     _updateSensitivity(sensitive) {
         this._authPrompt.updateSensitivity(sensitive);
 
@@ -574,7 +595,10 @@ var UnlockDialog = GObject.registerClass({
             opacity: 0,
             duration: 300,
             mode: Clutter.AnimationMode.EASE_OUT_QUAD,
-            onComplete: () => this._promptBox.hide(),
+            onComplete: () => {
+                this._promptBox.hide();
+                this._maybeDestroyAuthPrompt();
+            },
         });
 
         this._clock.ease({
@@ -585,6 +609,8 @@ var UnlockDialog = GObject.registerClass({
     }
 
     _showPrompt() {
+        this._ensureAuthPrompt();
+
         if (this._activePage == this._promptBox)
             return;
 
@@ -654,6 +680,7 @@ var UnlockDialog = GObject.registerClass({
     }
 
     cancel() {
+        this._ensureAuthPrompt();
         this._authPrompt.cancel();
     }
 
@@ -663,6 +690,7 @@ var UnlockDialog = GObject.registerClass({
     }
 
     finish(onComplete) {
+        this._ensureAuthPrompt();
         this._authPrompt.finish(onComplete);
     }