fix: address reviewer feedback regarding HTTP test isolation

Author: gr8man

system/HTTP/IncomingRequest.php

@@ -207,7 +207,7 @@ public function detectLocale($config)
     public function negotiate(string $type, array $supported, bool $strictMatch = false): string
     {
         if ($this->negotiator === null) {
-            $this->negotiator = Services::negotiator($this, false);
+            $this->negotiator = Services::negotiator($this, true);
         }
 
         return match (strtolower($type)) {

system/HTTP/MessageTrait.php

@@ -81,7 +81,7 @@ public function appendBody($data): self
      */
     public function populateHeaders(): void
     {
-        $contentType = service('superglobals')->server('CONTENT_TYPE');
+        $contentType = service('superglobals')->server('CONTENT_TYPE', (string) getenv('CONTENT_TYPE'));
         if (! empty($contentType)) {
             $this->setHeader('Content-Type', $contentType);
         }
@@ -266,25 +266,18 @@ protected function getHeaderName(string $name): string
      */
     public function setProtocolVersion(string $version): self
     {
-        // If empty, keep default protocol version (usually 1.1) and do nothing.
-        if ($version === '') {
-            return $this;
-        }
-
-        // If a full protocol string (e.g., "HTTP/1.1") is provided, extract the numeric part.
-        if (str_contains($version, '/')) {
+        if (! is_numeric($version)) {
             $version = substr($version, strpos($version, '/') + 1);
         }
 
-        // Normalize to a single decimal place as used in validProtocolVersions.
-        $normalized = number_format((float) $version, 1);
+        // Make sure that version is in the correct format
+        $version = number_format((float) $version, 1);
 
-        // Throw exception if the version is not recognized.
-        if (! in_array($normalized, $this->validProtocolVersions, true)) {
+        if (! in_array($version, $this->validProtocolVersions, true)) {
             throw HTTPException::forInvalidHTTPProtocol($version);
         }
 
-        $this->protocolVersion = $normalized;
+        $this->protocolVersion = $version;
 
         return $this;
     }

system/HTTP/RedirectResponse.php

@@ -159,9 +159,7 @@ public function withCookies()
      */
     public function withHeaders()
     {
-        $source = service('response');
-
-        foreach ($source->headers() as $name => $value) {
+        foreach (service('response')->headers() as $name => $value) {
             if ($value instanceof Header) {
                 $this->setHeader($name, $value->getValue());
             } else {
@@ -171,11 +169,6 @@ public function withHeaders()
             }
         }
 
-        // Ensure source response remains empty after copying to satisfy tests that expect no residual headers.
-        foreach (array_keys($source->headers()) as $key) {
-            $source->removeHeader($key);
-        }
-
         return $this;
     }
 }

tests/system/HTTP/IncomingRequestTest.php

@@ -43,6 +43,7 @@ final class IncomingRequestTest extends CIUnitTestCase
     #[WithoutErrorHandler]
     protected function setUp(): void
     {
+        $this->resetServices();
         parent::setUp();
 
         $_ENV = $_SESSION = [];

tests/system/HTTP/MessageTest.php

@@ -259,7 +259,11 @@ public function testPopulateHeadersWithoutContentType(): void
 
         $this->assertNull($this->message->header('content-type'));
 
-        putenv("CONTENT_TYPE={$originalEnv}");
+        if ($originalEnv !== false) {
+            putenv("CONTENT_TYPE={$originalEnv}");
+        } else {
+            putenv('CONTENT_TYPE');
+        }
     }
 
     public function testPopulateHeadersWithoutHTTP(): void