Add missing file extension if file does not have one

lib/pleroma/upload.ex

@@ -86,9 +86,14 @@ def upload_path do
   end
 
   defp create_name(uuid, ext, type) do
-    if type == "application/octet-stream" do
+    case type do
+      "application/octet-stream" ->
         String.downcase(Enum.join([uuid, ext], "."))
-    else
+
+      "audio/mpeg" ->
+        String.downcase(Enum.join([uuid, "mp3"], "."))
+
+      _ ->
         String.downcase(Enum.join([uuid, List.last(String.split(type, "/"))], "."))
     end
   end
@@ -104,10 +109,24 @@ defp get_uuid(file, should_dedupe) do
   defp get_name(file, uuid, type, should_dedupe) do
     if should_dedupe do
       create_name(uuid, List.last(String.split(file.filename, ".")), type)
+    else
+      unless String.contains?(file.filename, ".") do
+        case type do
+          "image/png" -> file.filename <> ".png"
+          "image/jpeg" -> file.filename <> ".jpg"
+          "image/gif" -> file.filename <> ".gif"
+          "video/webm" -> file.filename <> ".webm"
+          "video/mp4" -> file.filename <> ".mp4"
+          "audio/mpeg" -> file.filename <> ".mp3"
+          "audio/ogg" -> file.filename <> ".ogg"
+          "audio/wav" -> file.filename <> ".wav"
+          _ -> file.filename
+        end
       else
         file.filename
       end
     end
+  end
 
   defp get_upload_path(uuid, should_dedupe) do
     if should_dedupe do

test/upload_test.exs

@@ -43,5 +43,18 @@ test "fixes incorrect content type" do
       data = Upload.store(file, true)
       assert hd(data["url"])["mediaType"] == "image/jpeg"
     end
+
+    test "adds missing extension" do
+      File.cp!("test/fixtures/image.jpg", "test/fixtures/image_tmp.jpg")
+
+      file = %Plug.Upload{
+        content_type: "image/jpg",
+        path: Path.absname("test/fixtures/image_tmp.jpg"),
+        filename: "an [image"
+      }
+
+      data = Upload.store(file, false)
+      assert data["name"] == "an [image.jpg"
+    end
   end
 end