Allow cookie collections to store duplicates.

Duplicate cookie names are required for Http\Client use cases. Because
a client can make requests to multiple hosts, we need to store and track
all the cookies. This seemed preferrable to having a cookie collection
per domain in the client.

src/Http/Cookie/CookieCollection.php

@@ -65,20 +65,22 @@ public function count()
     /**
      * Add a cookie and get an updated collection.
      *
+     * Cookie names do not have to be unique in a collection, but
+     * having duplicate cookie names will change how get() behaves.
+     *
      * @param \Cake\Http\Cookie\CookieInterface $cookie Cookie instance to add.
      * @return static
      */
     public function add(CookieInterface $cookie)
     {
-        $key = mb_strtolower($cookie->getName());
         $new = clone $this;
-        $new->cookies[$key] = $cookie;
+        $new->cookies[] = $cookie;
 
         return $new;
     }
 
     /**
-     * Get a cookie by name
+     * Get the first cookie by name.
      *
      * If the provided name matches a URL (matches `#^https?://#`) this method
      * will assume you want a list of cookies that match that URL. This is
@@ -91,8 +93,10 @@ public function add(CookieInterface $cookie)
     public function get($name)
     {
         $key = mb_strtolower($name);
-        if (isset($this->cookies[$key])) {
-            return $this->cookies[$key];
+        foreach ($this->cookies as $cookie) {
+            if (mb_strtolower($cookie->getName()) === $key) {
+                return $cookie;
+            }
         }
 
         return null;
@@ -106,11 +110,18 @@ public function get($name)
      */
     public function has($name)
     {
-        return isset($this->cookies[mb_strtolower($name)]);
+        $key = mb_strtolower($name);
+        foreach ($this->cookies as $cookie) {
+            if (mb_strtolower($cookie->getName()) === $key) {
+                return true;
+            }
+        }
+
+        return false;
     }
 
     /**
-     * Remove a cookie from the collection and get a new collection
+     * Create a new collection with all cookies matching $name removed.
      *
      * If the cookie is not in the collection, this method will do nothing.
      *
@@ -120,7 +131,12 @@ public function has($name)
     public function remove($name)
     {
         $new = clone $this;
-        unset($new->cookies[mb_strtolower($name)]);
+        $key = mb_strtolower($name);
+        foreach ($new->cookies as $i => $cookie) {
+            if (mb_strtolower($cookie->getName()) === $key) {
+                unset($new->cookies[$i]);
+            }
+        }
 
         return $new;
     }
@@ -189,8 +205,7 @@ public function addFromResponse(ResponseInterface $response, RequestInterface $r
             if ($expires && $expires <= time()) {
                 continue;
             }
-            $key = mb_strtolower($cookie->getName());
-            $new->cookies[$key] = $cookie;
+            $new->cookies[] = $cookie;
         }
 
         return $new;

tests/TestCase/Http/Cookie/CookieCollectionTest.php

@@ -92,12 +92,24 @@ public function testAdd()
         $this->assertFalse($collection->has('remember_me'), 'Original instance not modified');
         $this->assertTrue($new->has('remember_me'));
         $this->assertSame($remember, $new->get('remember_me'));
+    }
 
+    /**
+     * Cookie collections need to support duplicate cookie names because
+     * of use cases in Http\Client
+     *
+     * @return void
+     */
+    public function testAddDuplicates()
+    {
+        $remember = new Cookie('remember_me', 'yes');
         $rememberNo = new Cookie('remember_me', 'no');
-        $second = $new->add($remember)->add($rememberNo);
-        $this->assertCount(1, $second);
-        $this->assertNotSame($second, $new);
-        $this->assertSame($rememberNo, $second->get('remember_me'));
+        $collection = new CookieCollection([]);
+        $new = $collection->add($remember)->add($rememberNo);
+
+        $this->assertCount(2, $new);
+        $this->assertNotSame($new, $collection);
+        $this->assertSame($remember, $new->get('remember_me'), 'get() fetches first cookie');
     }
 
     /**
@@ -205,6 +217,7 @@ public function testAddFromResponse()
         $this->assertSame('/app', $new->get('test')->getPath(), 'cookies should inherit request path');
         $this->assertSame('/', $new->get('expiring')->getPath(), 'path attribute should be used.');
 
+        $this->assertSame(0, $new->get('test')->getExpiry(), 'No expiry');
         $this->assertSame(0, $new->get('session')->getExpiry(), 'No expiry');
         $this->assertSame(
             '2021-06-09 10:18:14',