fix(http): treat an empty proxy_url as no proxy

test/pleroma/http/adapter_helper/hackney_test.exs

@@ -58,6 +58,13 @@ defmodule Pleroma.HTTP.AdapterHelper.HackneyTest do
                {:socks5, ~c"::1", 9050}
     end
 
+    # AdminFE stores an empty field as "", and Hackney 4 fails every request with it.
+    test "ignores an empty proxy_url", %{uri: uri} do
+      clear_config([:http, :proxy_url], "")
+
+      refute Keyword.has_key?(Hackney.options([], uri), :proxy)
+    end
+
     test "respect connection opts and no proxy", %{uri: uri} do
       opts = Hackney.options([a: 2, b: 1], uri)
 

test/pleroma/http/adapter_helper_test.exs

@@ -12,6 +12,12 @@ defmodule Pleroma.HTTP.AdapterHelperTest do
       assert AdapterHelper.format_proxy(nil) == nil
     end
 
+    test "with an empty string" do
+      assert ExUnit.CaptureLog.capture_log(fn ->
+               assert AdapterHelper.format_proxy("") == nil
+             end) == ""
+    end
+
     test "with string" do
       assert AdapterHelper.format_proxy("127.0.0.1:8123") == {{127, 0, 0, 1}, 8123}
     end