Fixes #1659: Do not try to read response body if request was HEAD

spec/std/http/client_spec.cr

@@ -41,6 +41,20 @@ module HTTP
     typeof(Client.get(URI.parse("http://www.example.com")))
     typeof(Client.get("http://www.example.com"))
 
+    it "doesn't read the body if request was HEAD" do
+      resp_get = TestServer.open("localhost", 8080, 0) do
+        client = Client.new("localhost", 8080)
+        break client.get("/")
+      end
+
+      TestServer.open("localhost", 8080, 0) do
+        client = Client.new("localhost", 8080)
+        resp_head = client.head("/")
+        resp_head.headers.should eq(resp_get.headers)
+        resp_head.body.should eq("")
+      end
+    end
+
     it "raises if URI is missing scheme" do
       expect_raises(ArgumentError) do
         HTTP::Client.get "www.example.com"

spec/std/http/response_spec.cr

@@ -83,6 +83,16 @@ module HTTP
       end
     end
 
+    it "parses response ignoring body" do
+      response = Response.from_io(StringIO.new("HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nContent-Length: 5\r\n\r\nhelloworld"), true)
+      response.version.should eq("HTTP/1.1")
+      response.status_code.should eq(200)
+      response.status_message.should eq("OK")
+      response.headers["content-type"].should eq("text/plain")
+      response.headers["content-length"].should eq("5")
+      response.body.should eq("")
+    end
+
     it "doesn't sets content length for 1xx, 204 or 304" do
       [100, 101, 204, 304].each do |status|
         response = Response.new(status)

src/http/client/client.cr

@@ -285,7 +285,7 @@ class HTTP::Client
     request.headers["User-agent"] ||= "Crystal"
     request.to_io(socket)
     socket.flush
-    HTTP::Response.from_io(socket).tap do |response|
+    HTTP::Response.from_io(socket, request.ignore_body?).tap do |response|
       close unless response.keep_alive?
     end
   end
@@ -303,7 +303,7 @@ class HTTP::Client
     request.headers["User-agent"] ||= "Crystal"
     request.to_io(socket)
     socket.flush
-    HTTP::Response.from_io(socket) do |response|
+    HTTP::Response.from_io(socket, request.ignore_body?) do |response|
       value = yield response
       response.body_io.try &.close
       close unless response.keep_alive?

src/http/common.cr

@@ -1,17 +1,25 @@
 module HTTP
   DATE_PATTERNS = {"%a, %d %b %Y %H:%M:%S %z", "%A, %d-%b-%y %H:%M:%S %z", "%a %b %e %H:%M:%S %Y"}
 
-  def self.parse_headers_and_body(io, mandatory_body = false)
+  enum BodyType
+    OnDemand
+    Prohibited
+    Mandatory
+  end
+
+  def self.parse_headers_and_body(io, body_type = BodyType::OnDemand : BodyType)
     headers = Headers.new
 
     while line = io.gets
       if line == "\r\n" || line == "\n"
         body = nil
-        if content_length = headers["Content-length"]?
+        if body_type.prohibited?
+          body = nil
+        elsif content_length = headers["Content-length"]?
           body = FixedLengthContent.new(io, content_length.to_i)
         elsif headers["Transfer-encoding"]? == "chunked"
           body = ChunkedContent.new(io)
-        elsif mandatory_body
+        elsif body_type.mandatory?
           body = UnknownLengthContent.new(io)
         end
 

src/http/request.cr

@@ -29,6 +29,10 @@ class HTTP::Request
     HTTP.keep_alive?(self)
   end
 
+  def ignore_body?
+    @method == "HEAD"
+  end
+
   def to_io(io)
     io << @method << " " << resource << " " << @version << "\r\n"
     cookies = @cookies

src/http/response.cr

@@ -81,22 +81,24 @@ class HTTP::Response
     version == "HTTP/1.1"
   end
 
-  def self.from_io(io)
-    from_io(io) do |response|
+  def self.from_io(io, ignore_body = false)
+    from_io(io, ignore_body) do |response|
       response.consume_body_io
       return response
     end
   end
 
-  def self.from_io(io, &block)
+  def self.from_io(io, ignore_body = false, &block)
     line = io.gets
     if line
       http_version, status_code, status_message = line.split(3)
       status_code = status_code.to_i
       status_message = status_message.chomp
-      mandatory_body = mandatory_body?(status_code)
+      body_type = HTTP::BodyType::OnDemand
+      body_type = HTTP::BodyType::Mandatory if mandatory_body?(status_code)
+      body_type = HTTP::BodyType::Prohibited if ignore_body
 
-      HTTP.parse_headers_and_body(io, mandatory_body) do |headers, body|
+      HTTP.parse_headers_and_body(io, body_type) do |headers, body|
         return yield new status_code, nil, headers, status_message, http_version, body
       end
     end