From 0feafcc20cec168258f592b9d509c1e6ccc8efba Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Fri, 9 Apr 2021 10:30:27 -0500
Subject: [PATCH 1/3] Use URI.merge to prevent concatenating two canonical URLs
 when a custom instance thumbnail was uploaded via AdminFE

---
 lib/pleroma/web/mastodon_api/views/instance_view.ex | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/pleroma/web/mastodon_api/views/instance_view.ex b/lib/pleroma/web/mastodon_api/views/instance_view.ex
index 73205fb6d..dac68d8e6 100644
--- a/lib/pleroma/web/mastodon_api/views/instance_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/instance_view.ex
@@ -23,7 +23,8 @@ defmodule Pleroma.Web.MastodonAPI.InstanceView do
         streaming_api: Pleroma.Web.Endpoint.websocket_url()
       },
       stats: Pleroma.Stats.get_stats(),
-      thumbnail: Pleroma.Web.base_url() <> Keyword.get(instance, :instance_thumbnail),
+      thumbnail:
+        URI.merge(Pleroma.Web.base_url(), Keyword.get(instance, :instance_thumbnail)) |> to_string,
       languages: ["en"],
       registrations: Keyword.get(instance, :registrations_open),
       approval_required: Keyword.get(instance, :account_approval_required),

From 9fbcdc15b11dedf27bc5c78d09048ba354906c16 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Tue, 13 Apr 2021 10:52:53 -0500
Subject: [PATCH 2/3] Validate custom instance thumbnail set via AdminAPI
 produces correct URL

---
 CHANGELOG.md                                  |  1 +
 .../controllers/config_controller_test.exs    | 42 +++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6c45cad85..1553245e5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 
 - Try to save exported ConfigDB settings (migrate_from_db) in the system temp directory if default location is not writable.
+- Uploading custom instance thumbnail via AdminAPI/AdminFE generated invalid URL to the image
 
 ## [2.3.0] - 2020-03-01
 
diff --git a/test/pleroma/web/admin_api/controllers/config_controller_test.exs b/test/pleroma/web/admin_api/controllers/config_controller_test.exs
index 578a4c914..71151712e 100644
--- a/test/pleroma/web/admin_api/controllers/config_controller_test.exs
+++ b/test/pleroma/web/admin_api/controllers/config_controller_test.exs
@@ -1410,6 +1410,48 @@ defmodule Pleroma.Web.AdminAPI.ConfigControllerTest do
                "need_reboot" => false
              }
     end
+
+    test "custom instance thumbnail", %{conn: conn} do
+      clear_config([:instance])
+
+      params = %{
+        "group" => ":pleroma",
+        "key" => ":instance",
+        "value" => [
+          %{
+            "tuple" => [
+              ":instance_thumbnail",
+              "https://example.com/media/new_thumbnail.jpg"
+            ]
+          }
+        ]
+      }
+
+      res =
+        assert conn
+               |> put_req_header("content-type", "application/json")
+               |> post("/api/pleroma/admin/config", %{"configs" => [params]})
+               |> json_response_and_validate_schema(200)
+
+      assert res == %{
+               "configs" => [
+                 %{
+                   "db" => [":instance_thumbnail"],
+                   "group" => ":pleroma",
+                   "key" => ":instance",
+                   "value" => params["value"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert res =
+               conn
+               |> get("/api/v1/instance")
+               |> json_response_and_validate_schema(200)
+
+      assert res = %{"thumbnail" => "https://example.com/media/new_thumbnail.jpg"}
+    end
   end
 
   describe "GET /api/pleroma/admin/config/descriptions" do

From cdd271b0655799e65bb9a13016dc82441ec34f87 Mon Sep 17 00:00:00 2001
From: Mark Felder <feld@feld.me>
Date: Tue, 13 Apr 2021 10:55:54 -0500
Subject: [PATCH 3/3] Fix assignment / assertion

---
 .../web/admin_api/controllers/config_controller_test.exs      | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/pleroma/web/admin_api/controllers/config_controller_test.exs b/test/pleroma/web/admin_api/controllers/config_controller_test.exs
index 71151712e..c4d07d61c 100644
--- a/test/pleroma/web/admin_api/controllers/config_controller_test.exs
+++ b/test/pleroma/web/admin_api/controllers/config_controller_test.exs
@@ -1445,8 +1445,8 @@ defmodule Pleroma.Web.AdminAPI.ConfigControllerTest do
                "need_reboot" => false
              }
 
-      assert res =
-               conn
+      _res =
+        assert conn
                |> get("/api/v1/instance")
                |> json_response_and_validate_schema(200)