From 88098cedef2204f27acff4608c67270b0054e77c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20M=C3=BCller?= <straightshoota@gmail.com>
Date: Tue, 9 Mar 2021 15:26:48 +0100
Subject: [PATCH 1/2] Use each_value instead of values.each

---
 src/http/cookie.cr | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/http/cookie.cr b/src/http/cookie.cr
index 65879c6cbdb8..8660eba9f754 100644
--- a/src/http/cookie.cr
+++ b/src/http/cookie.cr
@@ -272,8 +272,8 @@ module HTTP
     end
 
     # Yields each `HTTP::Cookie` in the collection.
-    def each(&block : Cookie ->)
-      @cookies.values.each do |cookie|
+    def each(& : Cookie ->)
+      @cookies.each_value do |cookie|
         yield cookie
       end
     end

From 0f0640583e18e4bc29b31f97ccdbff3a8a5cd899 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20M=C3=BCller?= <straightshoota@gmail.com>
Date: Tue, 9 Mar 2021 15:28:52 +0100
Subject: [PATCH 2/2] Override headers["Cookie"] and build string without
 intermediate

---
 src/http/cookie.cr | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/http/cookie.cr b/src/http/cookie.cr
index 8660eba9f754..fcf79b73431b 100644
--- a/src/http/cookie.cr
+++ b/src/http/cookie.cr
@@ -297,8 +297,15 @@ module HTTP
     # given `HTTP::Headers` instance and returns it. Removes any existing
     # `Cookie` headers in it.
     def add_request_headers(headers)
-      headers.delete("Cookie")
-      headers.add("Cookie", map(&.to_cookie_header).join("; ")) unless empty?
+      if empty?
+        headers.delete("Cookie")
+      else
+        capacity = sum { |cookie| cookie.name.bytesize + cookie.value.bytesize + 1 }
+        capacity += (size - 1) * 2
+        headers["Cookie"] = String.build(capacity) do |io|
+          join(io, "; ", &.to_cookie_header(io))
+        end
+      end
 
       headers
     end