diff -Nru gnome-flashback-3.24.0/debian/changelog gnome-flashback-3.24.0/debian/changelog
--- gnome-flashback-3.24.0/debian/changelog	2017-07-27 08:19:25.000000000 +0000
+++ gnome-flashback-3.24.0/debian/changelog	2017-07-31 17:40:12.000000000 +0000
@@ -1,3 +1,10 @@
+gnome-flashback (3.24.0-1ubuntu2) artful; urgency=medium
+
+  * Backport upstream commit to fix the disabled Authenticate button in the
+    Authentication Agent dialog (polkit-password-entry.diff; LP: #1698994).
+
+ -- Dmitry Shachnev <mitya57@ubuntu.com>  Mon, 31 Jul 2017 20:40:12 +0300
+
 gnome-flashback (3.24.0-1ubuntu1) artful; urgency=medium
 
   * Merge with Debian experimental, remaining changes:
diff -Nru gnome-flashback-3.24.0/debian/patches/polkit-password-entry.diff gnome-flashback-3.24.0/debian/patches/polkit-password-entry.diff
--- gnome-flashback-3.24.0/debian/patches/polkit-password-entry.diff	1970-01-01 00:00:00.000000000 +0000
+++ gnome-flashback-3.24.0/debian/patches/polkit-password-entry.diff	2017-07-31 17:40:12.000000000 +0000
@@ -0,0 +1,27 @@
+Description: polkit: do not disable password entry
+ If we have already selected user we should not disable password
+ entry and authentication button.
+Origin: upstream, https://git.gnome.org/browse/gnome-flashback/commit/?id=6d78851ba34cb618
+Last-Update: 2017-07-31
+
+--- a/gnome-flashback/libpolkit/flashback-polkit-dialog.c
++++ b/gnome-flashback/libpolkit/flashback-polkit-dialog.c
+@@ -494,11 +494,15 @@
+ 
+   if (g_strv_length (dialog->users) > 1)
+     {
++      gboolean sensitive;
++
+       setup_users_store (dialog);
+ 
+-      gtk_widget_set_sensitive (dialog->prompt_label, FALSE);
+-      gtk_widget_set_sensitive (dialog->password_entry, FALSE);
+-      gtk_widget_set_sensitive (dialog->auth_button, FALSE);
++      sensitive = dialog->selected_user != NULL ? TRUE : FALSE;
++
++      gtk_widget_set_sensitive (dialog->prompt_label, sensitive);
++      gtk_widget_set_sensitive (dialog->password_entry, sensitive);
++      gtk_widget_set_sensitive (dialog->auth_button, sensitive);
+     }
+   else
+     {
diff -Nru gnome-flashback-3.24.0/debian/patches/series gnome-flashback-3.24.0/debian/patches/series
--- gnome-flashback-3.24.0/debian/patches/series	2017-07-27 08:19:25.000000000 +0000
+++ gnome-flashback-3.24.0/debian/patches/series	2017-07-31 17:40:12.000000000 +0000
@@ -1,3 +1,4 @@
 run-systemd-session.diff
 support-indicator-keyboard.diff
 fix-touchscreen-crashes.diff
+polkit-password-entry.diff