fix(media_proxy): serve static previews instead of redirecting to the main host

Ported from Akkoma 4a810bb2e.

Co-authored-by: Oneric <oneric@oneric.stub>

changelog.d/media-proxy-static-redirect.fix

@@ -0,0 +1 @@
+Media proxy: serve a preview for static=true on non-GIF files instead of redirecting to the main endpoint host

lib/pleroma/web/media_proxy/media_proxy_controller.ex

@@ -7,7 +7,6 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
 
   alias Pleroma.Config
   alias Pleroma.Helpers.MediaHelper
-  alias Pleroma.Helpers.UriHelper
   alias Pleroma.ReverseProxy
   alias Pleroma.Web.MediaProxy
   alias Plug.Conn
@@ -67,9 +66,6 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
         static and content_type == "image/gif" ->
           handle_jpeg_preview(conn, media_proxy_url)
 
-        static ->
-          drop_static_param_and_redirect(conn)
-
         content_type == "image/gif" ->
           conn
           |> put_status(301)
@@ -166,15 +162,6 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyController do
     end
   end
 
-  defp drop_static_param_and_redirect(conn) do
-    uri_without_static_param =
-      conn
-      |> current_url()
-      |> UriHelper.modify_uri_params(%{}, ["static"])
-
-    redirect(conn, external: uri_without_static_param)
-  end
-
   defp fallback_on_preview_error(conn, media_proxy_url) do
     redirect(conn, external: media_proxy_url)
   end

test/pleroma/web/media_proxy/media_proxy_controller_test.exs

@@ -252,22 +252,27 @@ defmodule Pleroma.Web.MediaProxy.MediaProxyControllerTest do
       assert redirected_to(response, 301) == media_proxy_url
     end
 
-    test "with `static` param and non-GIF image preview requested, " <>
-           "redirects to media preview proxy URI without `static` param",
+    test "with `static` param and non-GIF image preview requested, responds with a preview",
          %{
            conn: conn,
            url: url,
            media_proxy_url: media_proxy_url
          } do
+      assert_dependencies_installed()
+
       Tesla.Mock.mock(fn
         %{method: :head, url: ^media_proxy_url} ->
           %Tesla.Env{status: 200, body: "", headers: [{"content-type", "image/jpeg"}]}
+
+        %{method: :get, url: ^media_proxy_url} ->
+          %Tesla.Env{status: 200, body: File.read!("test/fixtures/image.jpg")}
       end)
 
       response = get(conn, url <> "?static=true")
 
-      assert response.status == 302
-      assert redirected_to(response) == url
+      assert response.status == 200
+      assert Conn.get_resp_header(response, "content-type") == ["image/jpeg"]
+      assert response.resp_body != ""
     end
 
     test "with :min_content_length setting not matched by Content-Length header, " <>