Correctly parse content types with multiple profiles

Multiple profiles can be specified as a space-separated list
and the possibility of additional profiles is explicitly brought up
in ActivityStream spec

CHANGELOG.md

@@ -17,6 +17,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## Fixed
 - Meilisearch: order of results returned from our REST API now actually matches how Meilisearch ranks results
+- AP objects with additional JSON-LD profiles beyond ActivityStreams can now be fetched
 
 ## Changed
 - Refactored Rich Media to cache the content in the database. Fetching operations that could block status rendering have been eliminated.

lib/pleroma/object/fetcher.ex

@@ -369,8 +369,12 @@ def get_object(id) do
         {"activity+json", _} ->
           {:ok, final_id, body}
 
-        {"ld+json", %{"profile" => "https://www.w3.org/ns/activitystreams"}} ->
-          {:ok, final_id, body}
+        {"ld+json", %{"profile" => profiles}} ->
+          if "https://www.w3.org/ns/activitystreams" in String.split(profiles) do
+            {:ok, final_id, body}
+          else
+            {:error, {:content_type, content_type}}
+          end
 
         _ ->
           {:error, {:content_type, content_type}}

test/pleroma/object/fetcher_test.exs

@@ -754,7 +754,7 @@ test "should return ok if the content type is application/activity+json" do
       assert {:ok, _, "{}"} = Fetcher.get_object("https://mastodon.social/2")
     end
 
-    test "should return ok if the content type is application/ld+json with a profile" do
+    test "should return ok if the content type is application/ld+json with the ActivityStream profile" do
       Tesla.Mock.mock(fn
         %{
           method: :get,
@@ -774,6 +774,26 @@ test "should return ok if the content type is application/ld+json with a profile
       assert {:ok, _, "{}"} = Fetcher.get_object("https://mastodon.social/2")
     end
 
+    test "should return ok if the content type is application/ld+json with several profiles" do
+      Tesla.Mock.mock(fn
+        %{
+          method: :get,
+          url: "https://mastodon.social/2"
+        } ->
+          %Tesla.Env{
+            status: 200,
+            url: "https://mastodon.social/2",
+            headers: [
+              {"content-type",
+               "application/ld+json; profile=\"https://example.org/ns/superduperspec https://www.w3.org/ns/activitystreams\""}
+            ],
+            body: "{}"
+          }
+      end)
+
+      assert {:ok, _, "{}"} = Fetcher.get_object("https://mastodon.social/2")
+    end
+
     test "should not return ok with other content types" do
       Tesla.Mock.mock(fn
         %{