Support Rack 3 and fix tests on Rack 3

Most changes are to the tests to avoid uppercase characters in header
keys, which are no longer allowed in rack 3 (to allow for O(1) access).

This also changes a few places where an array of headers was used to
switch to a hash, as a hash is requierd in Rack 3.

Newer versions of curl use a 000 http_code for invalid http codes,
so switch from "42 -eq" to "500 -ne" in the test, as Rack::Lint will
always raise a 500 error.

There is one test that fails on OpenBSD when opening a fifo.  This is
unrelated to unicorn as far as I can see, so skip the remaining part
of the test in that case on OpenBSD.

Tests still pass on Rack 2, and presumably Rack 1 as well, though
I didn't test Rack 1.

Co-authored-by: Eric Wong <bofh@yhbt.net>

2 files changed, 18 insertions, 22 deletions

diff --git a/lib/unicorn/http_response.rb b/lib/unicorn/http_response.rb
index b23e521..19469b4 100644
--- a/lib/unicorn/http_response.rb
+++ b/lib/unicorn/http_response.rb
@@ -19,6 +19,18 @@ module Unicorn::HttpResponse
       "#{code} #{STATUS_CODES[code]}\r\n\r\n"
   end
 
+  def append_header(buf, key, value)
+    case value
+    when Array # Rack 3
+      value.each { |v| buf << "#{key}: #{v}\r\n" }
+    when /\n/ # Rack 2
+      # avoiding blank, key-only cookies with /\n+/
+      value.split(/\n+/).each { |v| buf << "#{key}: #{v}\r\n" }
+    else
+      buf << "#{key}: #{value}\r\n"
+    end
+  end
+
   # writes the rack_response to socket as an HTTP response
   def http_response_write(socket, status, headers, body,
                           req = Unicorn::HttpRequest.new)
@@ -40,12 +52,7 @@ module Unicorn::HttpResponse
           # key in Rack < 1.5
           hijack = value
         else
-          if value =~ /\n/
-            # avoiding blank, key-only cookies with /\n+/
-            value.split(/\n+/).each { |v| buf << "#{key}: #{v}\r\n" }
-          else
-            buf << "#{key}: #{value}\r\n"
-          end
+          append_header(buf, key, value)
         end
       end
       socket.write(buf << "\r\n".freeze)
diff --git a/lib/unicorn/http_server.rb b/lib/unicorn/http_server.rb
index 0ba24d8..348e745 100644
--- a/lib/unicorn/http_server.rb
+++ b/lib/unicorn/http_server.rb
@@ -573,22 +573,11 @@ class Unicorn::HttpServer
   end
 
   def e103_response_write(client, headers)
-    response = if @request.response_start_sent
-      "103 Early Hints\r\n"
-    else
-      "HTTP/1.1 103 Early Hints\r\n"
-    end
-
-    headers.each_pair do |k, vs|
-      next if !vs || vs.empty?
-      values = vs.to_s.split("\n".freeze)
-      values.each do |v|
-        response << "#{k}: #{v}\r\n"
-      end
-    end
-    response << "\r\n".freeze
-    response << "HTTP/1.1 ".freeze if @request.response_start_sent
-    client.write(response)
+    rss = @request.response_start_sent
+    buf = rss ? "103 Early Hints\r\n" : "HTTP/1.1 103 Early Hints\r\n"
+    headers.each { |key, value| append_header(buf, key, value) }
+    buf << (rss ? "\r\nHTTP/1.1 ".freeze : "\r\n".freeze)
+    client.write(buf)
   end
 
   def e100_response_write(client, env)