Reverse emitStatusLine() and emitHeaders() calls

To ensure that the emitted response will always be correct according
with the response object.

src/Response/SapiEmitter.php

@@ -26,8 +26,8 @@ public function emit(ResponseInterface $response)
     {
         $this->assertNoPreviousOutput();
 
-        $this->emitStatusLine($response);
         $this->emitHeaders($response);
+        $this->emitStatusLine($response);
         $this->emitBody($response);
     }
 

src/Response/SapiEmitterTrait.php

@@ -38,7 +38,13 @@ private function assertNoPreviousOutput()
      * Emits the status line using the protocol version and status code from
      * the response; if a reason phrase is available, it, too, is emitted.
      *
+     * It's important to mention that, in order to prevent PHP from changing
+     * the status code of the emitted response, this method should be called
+     * after `emitHeaders()`
+     *
      * @param ResponseInterface $response
+     *
+     * @see \Zend\Diactoros\Response\SapiEmitterTrait::emitHeaders()
      */
     private function emitStatusLine(ResponseInterface $response)
     {

src/Response/SapiStreamEmitter.php

@@ -27,8 +27,8 @@ class SapiStreamEmitter implements EmitterInterface
     public function emit(ResponseInterface $response, $maxBufferLength = 8192)
     {
         $this->assertNoPreviousOutput();
-        $this->emitStatusLine($response);
         $this->emitHeaders($response);
+        $this->emitStatusLine($response);
 
         $range = $this->parseContentRange($response->getHeaderLine('Content-Range'));
 

test/Response/AbstractEmitterTest.php

@@ -66,9 +66,9 @@ public function testMultipleSetCookieHeadersAreNotReplaced()
         $this->emitter->emit($response);
 
         $expectedStack = [
-            ['header' => 'HTTP/1.1 200 OK', 'replace' => true, 'status_code' => 200],
             ['header' => 'Set-Cookie: foo=bar', 'replace' => false, 'status_code' => 200],
             ['header' => 'Set-Cookie: bar=baz', 'replace' => false, 'status_code' => 200],
+            ['header' => 'HTTP/1.1 200 OK', 'replace' => true, 'status_code' => 200],
         ];
 
         $this->assertSame($expectedStack, HeaderStack::stack());
@@ -84,9 +84,9 @@ public function testDoesNotLetResponseCodeBeOverriddenByPHP()
         $this->emitter->emit($response);
 
         $expectedStack = [
-            ['header' => 'HTTP/1.1 202 Accepted', 'replace' => true, 'status_code' => 202],
             ['header' => 'Location: http://api.my-service.com/12345678', 'replace' => true, 'status_code' => 202],
             ['header' => 'Content-Type: text/plain', 'replace' => true, 'status_code' => 202],
+            ['header' => 'HTTP/1.1 202 Accepted', 'replace' => true, 'status_code' => 202],
         ];
 
         $this->assertSame($expectedStack, HeaderStack::stack());

test/ServerTest.php

@@ -246,16 +246,23 @@ public function testEmitsHeadersWithMultipleValuesMultipleTimes()
      */
     public function testHeaderOrderIsHonoredWhenEmitted($stack)
     {
+        $header = array_pop($stack);
+        $this->assertContains('Content-Type: text/plain', $header);
+
         $header = array_pop($stack);
         $this->assertContains(
             'Set-Cookie: bar=baz; expires=Wed, 8 Oct 2014 10:30; path=/foo/bar; domain=example.com',
             $header
         );
+
         $header = array_pop($stack);
         $this->assertContains(
             'Set-Cookie: foo=bar; expires=Wed, 1 Oct 2014 10:30; path=/foo; domain=example.com',
             $header
         );
+
+        $header = array_pop($stack);
+        $this->assertContains('HTTP/1.1 200 OK', $header);
     }
 
     public function testListenPassesCallableArgumentToCallback()