From 45be1fe00e93fadab27a8e93e4537f11f6edd5eb Mon Sep 17 00:00:00 2001
From: rinpatch <rinpatch@sdf.org>
Date: Sat, 1 Aug 2020 17:59:50 +0300
Subject: [PATCH] ConnectionPool: fix gun open errors being returned without an
 error tuple

When gun shuts down due to the host being unreachable, the worker
process shuts down with the same shutdown reason since they are linked.
Gun doesn't have error tuples in it's shutdown reason though, so we need
to handle it in get_conn.

Closes #2008
---
 lib/pleroma/gun/connection_pool.ex | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/pleroma/gun/connection_pool.ex b/lib/pleroma/gun/connection_pool.ex
index 49e9885bb..f34602b73 100644
--- a/lib/pleroma/gun/connection_pool.ex
+++ b/lib/pleroma/gun/connection_pool.ex
@@ -10,6 +10,7 @@ defmodule Pleroma.Gun.ConnectionPool do
     ]
   end
 
+  @spec get_conn(URI.t(), keyword()) :: {:ok, pid()} | {:error, term()}
   def get_conn(uri, opts) do
     key = "#{uri.scheme}:#{uri.host}:#{uri.port}"
 
@@ -54,12 +55,14 @@ defmodule Pleroma.Gun.ConnectionPool do
 
       {:DOWN, ^ref, :process, ^worker_pid, reason} ->
         case reason do
-          {:shutdown, error} -> error
+          {:shutdown, {:error, _} = error} -> error
+          {:shutdown, error} -> {:error, error}
           _ -> {:error, reason}
         end
     end
   end
 
+  @spec release_conn(pid()) :: :ok
   def release_conn(conn_pid) do
     # :ets.fun2ms(fn {_, {worker_pid, {gun_pid, _, _, _}}} when gun_pid == conn_pid ->
     #    worker_pid end)