InlineQuotePolicy: don't add line breaks to markdown posts

lib/pleroma/web/activity_pub/mrf/inline_quote_policy.ex

@@ -6,8 +6,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.InlineQuotePolicy do
   @moduledoc "Force a quote line into the message content."
   @behaviour Pleroma.Web.ActivityPub.MRF.Policy
 
-  defp build_inline_quote(prefix, url) do
+  defp build_inline_quote(prefix, url, br) do
-    "<span class=\"quote-inline\"><br><br>#{prefix}: <a href=\"#{url}\">#{url}</a></span>"
+    "<span class=\"quote-inline\">#{String.duplicate("<br>", br)}#{prefix}: <a href=\"#{url}\">#{url}</a></span>"
   end
 
   defp filter_object(%{"quoteUrl" => quote_url} = object) do
@@ -17,7 +17,13 @@ defmodule Pleroma.Web.ActivityPub.MRF.InlineQuotePolicy do
       object
     else
       prefix = Pleroma.Config.get([:mrf_inline_quote, :prefix])
-      content = content <> build_inline_quote(prefix, quote_url)
+
+      inline_quote =
+        if String.ends_with?(content, "</p>"),
+          do: build_inline_quote(prefix, quote_url, 0),
+          else: build_inline_quote(prefix, quote_url, 2)
+
+      content = content <> inline_quote
       Map.put(object, "content", content)
     end
   end

test/pleroma/web/activity_pub/mrf/inline_quote_policy_test.exs

@@ -9,6 +9,25 @@ defmodule Pleroma.Web.ActivityPub.MRF.InlineQuotePolicyTest do
   test "adds quote URL to post content" do
     quote_url = "https://gleasonator.com/objects/1234"
 
+    activity = %{
+      "type" => "Create",
+      "actor" => "https://gleasonator.com/users/alex",
+      "object" => %{
+        "type" => "Note",
+        "content" => "Nice post",
+        "quoteUrl" => quote_url
+      }
+    }
+
+    {:ok, %{"object" => %{"content" => filtered}}} = InlineQuotePolicy.filter(activity)
+
+    assert filtered ==
+             "Nice post<span class=\"quote-inline\"><br><br>RT: <a href=\"https://gleasonator.com/objects/1234\">https://gleasonator.com/objects/1234</a></span>"
+  end
+
+  test "doesn't add line breaks to markdown posts" do
+    quote_url = "https://gleasonator.com/objects/1234"
+
     activity = %{
       "type" => "Create",
       "actor" => "https://gleasonator.com/users/alex",
@@ -22,7 +41,7 @@ defmodule Pleroma.Web.ActivityPub.MRF.InlineQuotePolicyTest do
     {:ok, %{"object" => %{"content" => filtered}}} = InlineQuotePolicy.filter(activity)
 
     assert filtered ==
-             "<p>Nice post</p><span class=\"quote-inline\"><br><br>RT: <a href=\"https://gleasonator.com/objects/1234\">https://gleasonator.com/objects/1234</a></span>"
+             "<p>Nice post</p><span class=\"quote-inline\">RT: <a href=\"https://gleasonator.com/objects/1234\">https://gleasonator.com/objects/1234</a></span>"
   end
 
   test "ignores Misskey quote posts" do