From 2deefc545278f2adf6b1bb7fc6de07b3efb98d61 Mon Sep 17 00:00:00 2001
From: Manabu Ejima <jemiam@gmail.com>
Date: Thu, 15 Dec 2016 01:45:10 +0900
Subject: [PATCH] Raise error when `stdout` or `stderr` is not writable

---
 lib/puma/runner.rb | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/puma/runner.rb b/lib/puma/runner.rb
index 72f37798d4..339c272d1e 100644
--- a/lib/puma/runner.rb
+++ b/lib/puma/runner.rb
@@ -107,12 +107,20 @@ def redirect_io
       append = @options[:redirect_append]
 
       if stdout
+        unless Dir.exists?(File.dirname(stdout))
+          raise "Cannot redirect STDOUT to #{stdout}"
+        end
+
         STDOUT.reopen stdout, (append ? "a" : "w")
         STDOUT.sync = true
         STDOUT.puts "=== puma startup: #{Time.now} ==="
       end
 
       if stderr
+        unless Dir.exists?(File.dirname(stderr))
+          raise "Cannot redirect STDERR to #{stderr}"
+        end
+
         STDERR.reopen stderr, (append ? "a" : "w")
         STDERR.sync = true
         STDERR.puts "=== puma startup: #{Time.now} ==="