http_response: drop bodies for non-compliant responses

Rack::Lint-compliant applications wouldn't have this problem;
but apparently public-facing Rack servers (webrick/puma/thin)
all implement this; so there is precedence for implementing
this in yahns itself.

2 files changed, 11 insertions, 10 deletions

diff --git a/lib/yahns/http_client.rb b/lib/yahns/http_client.rb
index 1cdaa0f..873dd73 100644
--- a/lib/yahns/http_client.rb
+++ b/lib/yahns/http_client.rb
@@ -189,9 +189,11 @@ class Yahns::HttpClient < Kgio::Socket # :nodoc:
       mkinput_preread # keep looping (@state == :body)
       true
     else # :lazy, false
-      status, headers, body = k.app.call(env = @hs.env)
+      env = @hs.env
+      hdr_only = env['REQUEST_METHOD'] == 'HEAD'.freeze
+      status, headers, body = k.app.call(env)
       return :ignore if app_hijacked?(env, body)
-      http_response_write(status, headers, body)
+      http_response_write(status, headers, body, hdr_only)
     end
   end
 
@@ -220,6 +222,7 @@ class Yahns::HttpClient < Kgio::Socket # :nodoc:
       env['SERVER_PORT'] = '443'.freeze
     end
 
+    hdr_only = env['REQUEST_METHOD'] == 'HEAD'.freeze
     # run the rack app
     status, headers, body = k.app.call(env)
     return :ignore if app_hijacked?(env, body)
@@ -229,7 +232,7 @@ class Yahns::HttpClient < Kgio::Socket # :nodoc:
     end
 
     # this returns :wait_readable, :wait_writable, :ignore, or nil:
-    http_response_write(status, headers, body)
+    http_response_write(status, headers, body, hdr_only)
   end
 
   # called automatically by kgio_write
diff --git a/lib/yahns/http_response.rb b/lib/yahns/http_response.rb
index d957df6..88ff9f9 100644
--- a/lib/yahns/http_response.rb
+++ b/lib/yahns/http_response.rb
@@ -9,7 +9,7 @@ require_relative 'wbuf_str'
 # You use it by simply doing:
 #
 #   status, headers, body = rack_app.call(env)
-#   http_response_write(status, headers, body)
+#   http_response_write(status, headers, body, env['REQUEST_METHOD']=='HEAD')
 #
 # Most header correctness (including Content-Length and Content-Type)
 # is the job of Rack, with the exception of the "Date" header.
@@ -118,13 +118,9 @@ module Yahns::HttpResponse # :nodoc:
     end
   end
 
-  def have_more?(value)
-    value.to_i > 0 && @hs.env['REQUEST_METHOD'] != 'HEAD'.freeze
-  end
-
   # writes the rack_response to socket as an HTTP response
   # returns :wait_readable, :wait_writable, :forget, or nil
-  def http_response_write(status, headers, body)
+  def http_response_write(status, headers, body, hdr_only)
     offset = 0
     count = hijack = nil
     k = self.class
@@ -133,6 +129,7 @@ module Yahns::HttpResponse # :nodoc:
 
     if @hs.headers?
       code = status.to_i
+      hdr_only ||= Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.include?(code)
       msg = Rack::Utils::HTTP_STATUS_CODES[code]
       buf = "#{response_start}#{msg ? %Q(#{code} #{msg}) : status}\r\n" \
             "Date: #{httpdate}\r\n".dup
@@ -150,7 +147,7 @@ module Yahns::HttpResponse # :nodoc:
           # allow Rack apps to tell us they want to drop the client
           alive = false if value =~ /\bclose\b/i
         when %r{\AContent-Length\z}i
-          flags |= MSG_MORE if have_more?(value)
+          flags |= MSG_MORE if value.to_i > 0 && !hdr_only
           kv_str(buf, key, value)
         when "rack.hijack"
           hijack = value
@@ -181,6 +178,7 @@ module Yahns::HttpResponse # :nodoc:
     end
 
     return response_hijacked(hijack) if hijack
+    return http_response_done(alive) if hdr_only
 
     if body.respond_to?(:to_path)
       @state = body = Yahns::StreamFile.new(body, alive, offset, count)