From e0a521bbfb3df5792d0c6879df71338a4c9e3f26 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Sat, 12 Jun 2021 12:41:12 -0500
Subject: [PATCH] Web Push notifications should not embed HTML for preserving
 newlines, so give it its own filtering

---
 lib/pleroma/web/metadata/utils.ex   | 17 -----------------
 lib/pleroma/web/push/impl.ex        | 21 +++++++++++++++++----
 test/pleroma/web/push/impl_test.exs | 25 +++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 21 deletions(-)

diff --git a/lib/pleroma/web/metadata/utils.ex b/lib/pleroma/web/metadata/utils.ex
index 4c763a877..dd80c3277 100644
--- a/lib/pleroma/web/metadata/utils.ex
+++ b/lib/pleroma/web/metadata/utils.ex
@@ -13,12 +13,6 @@ defmodule Pleroma.Web.Metadata.Utils do
   def filter_html_and_truncate(content, max_length \\ nil),
     do: do_filter_html_and_truncate(content, max_length)
 
-  def scrub_html_and_truncate(%{data: %{"content" => content}} = _object),
-    do: do_scrub_html_and_truncate(content)
-
-  def scrub_html_and_truncate(content, max_length \\ nil),
-    do: do_scrub_html_and_truncate(content, max_length)
-
   def user_name_string(user) do
     "#{user.name} " <>
       if user.local do
@@ -45,15 +39,4 @@ defmodule Pleroma.Web.Metadata.Utils do
     |> String.replace(~r/<br\s?\/?>/, "&#10;&#13;")
     |> Formatter.truncate(max_length)
   end
-
-  defp do_scrub_html_and_truncate(content, max_length \\ 200) when is_binary(content) do
-    # html content comes from DB already encoded
-    content
-    |> HtmlEntities.decode()
-    |> Emoji.Formatter.demojify()
-    |> String.replace(~r/<br\s?\/?>/, " ")
-    |> HTML.strip_tags()
-    |> HtmlEntities.decode()
-    |> Formatter.truncate(max_length)
-  end
 end
diff --git a/lib/pleroma/web/push/impl.ex b/lib/pleroma/web/push/impl.ex
index 83cbdc870..6d83df8ab 100644
--- a/lib/pleroma/web/push/impl.ex
+++ b/lib/pleroma/web/push/impl.ex
@@ -6,11 +6,13 @@ defmodule Pleroma.Web.Push.Impl do
   @moduledoc "The module represents implementation push web notification"
 
   alias Pleroma.Activity
+  alias Pleroma.Emoji
+  alias Pleroma.Formatter
+  alias Pleroma.HTML
   alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.Repo
   alias Pleroma.User
-  alias Pleroma.Web.Metadata.Utils
   alias Pleroma.Web.Push.Subscription
 
   require Logger
@@ -127,7 +129,7 @@ defmodule Pleroma.Web.Push.Impl do
   def format_body(_activity, actor, %{data: %{"type" => "ChatMessage", "content" => content}}, _) do
     case content do
       nil -> "@#{actor.nickname}: (Attachment)"
-      content -> "@#{actor.nickname}: #{Utils.scrub_html_and_truncate(content, 80)}"
+      content -> "@#{actor.nickname}: #{filter_html_and_truncate(content, 80)}"
     end
   end
 
@@ -137,7 +139,7 @@ defmodule Pleroma.Web.Push.Impl do
         %{data: %{"content" => content}},
         _mastodon_type
       ) do
-    "@#{actor.nickname}: #{Utils.scrub_html_and_truncate(content, 80)}"
+    "@#{actor.nickname}: #{filter_html_and_truncate(content, 80)}"
   end
 
   def format_body(
@@ -146,7 +148,7 @@ defmodule Pleroma.Web.Push.Impl do
         %{data: %{"content" => content}},
         _mastodon_type
       ) do
-    "@#{actor.nickname} repeated: #{Utils.scrub_html_and_truncate(content, 80)}"
+    "@#{actor.nickname} repeated: #{filter_html_and_truncate(content, 80)}"
   end
 
   def format_body(
@@ -192,4 +194,15 @@ defmodule Pleroma.Web.Push.Impl do
       type -> "New #{String.capitalize(type || "event")}"
     end
   end
+
+  defp filter_html_and_truncate(content, max_length) when is_binary(content) do
+    # html content comes from DB already encoded
+    content
+    |> HtmlEntities.decode()
+    |> Emoji.Formatter.demojify()
+    |> HTML.filter_tags(Pleroma.HTML.Scrubber.BreaksOnly)
+    |> HtmlEntities.decode()
+    |> String.replace(~r/<br\s?\/?>/, "\r\n")
+    |> Formatter.truncate(max_length)
+  end
 end
diff --git a/test/pleroma/web/push/impl_test.exs b/test/pleroma/web/push/impl_test.exs
index b3ca1a337..24304a317 100644
--- a/test/pleroma/web/push/impl_test.exs
+++ b/test/pleroma/web/push/impl_test.exs
@@ -359,4 +359,29 @@ defmodule Pleroma.Web.Push.ImplTest do
              }
     end
   end
+
+  test "body for create activity handles newlines" do
+    user = insert(:user, nickname: "bob")
+    _user2 = insert(:user, nickname: "alice")
+
+    {:ok, activity} =
+      CommonAPI.post(user, %{
+        status: """
+        @alice Line one
+        Line two
+        Line three
+        """
+      })
+
+    object = Object.normalize(activity, fetch: false)
+
+    assert Impl.format_body(
+             %{
+               activity: activity
+             },
+             user,
+             object
+           ) ==
+             "@bob: @alice Line one\r\nLine two\r\nLine three"
+  end
 end