AccountController: Allow removal / reset of user images.

lib/pleroma/user.ex

@@ -89,7 +89,7 @@ defmodule Pleroma.User do
     field(:keys, :string)
     field(:public_key, :string)
     field(:ap_id, :string)
-    field(:avatar, :map)
+    field(:avatar, :map, default: %{})
     field(:local, :boolean, default: true)
     field(:follower_address, :string)
     field(:following_address, :string)
@@ -539,14 +539,11 @@ defmodule Pleroma.User do
   end
 
   defp put_change_if_present(changeset, map_field, value_function) do
-    if value = get_change(changeset, map_field) do
-      with {:ok, new_value} <- value_function.(value) do
-        put_change(changeset, map_field, new_value)
-      else
-        _ -> changeset
-      end
+    with {:ok, value} <- fetch_change(changeset, map_field),
+         {:ok, new_value} <- value_function.(value) do
+      put_change(changeset, map_field, new_value)
     else
-      changeset
+      _ -> changeset
     end
   end
 

lib/pleroma/web/mastodon_api/controllers/account_controller.ex

@@ -148,6 +148,13 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
       |> Enum.filter(fn {_, value} -> not is_nil(value) end)
       |> Enum.into(%{})
 
+    # We use an empty string as a special value to reset
+    # avatars, banners, backgrounds
+    user_image_value = fn
+      "" -> {:ok, nil}
+      value -> {:ok, value}
+    end
+
     user_params =
       [
         :no_rich_text,
@@ -168,9 +175,9 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
       |> Maps.put_if_present(:name, params[:display_name])
       |> Maps.put_if_present(:bio, params[:note])
       |> Maps.put_if_present(:raw_bio, params[:note])
-      |> Maps.put_if_present(:avatar, params[:avatar])
-      |> Maps.put_if_present(:banner, params[:header])
-      |> Maps.put_if_present(:background, params[:pleroma_background_image])
+      |> Maps.put_if_present(:avatar, params[:avatar], user_image_value)
+      |> Maps.put_if_present(:banner, params[:header], user_image_value)
+      |> Maps.put_if_present(:background, params[:pleroma_background_image], user_image_value)
       |> Maps.put_if_present(
         :raw_fields,
         params[:fields_attributes],