Fix shallow Request clone sharing query/headers/config for pooled sends

src/Helpers/MiddlewarePipeline.php

@@ -37,6 +37,16 @@ public function __construct()
         $this->fatalPipeline = new Pipeline;
     }
 
+    /**
+     * Deep-clone internal pipelines so cloned requests do not share pipe state.
+     */
+    public function __clone(): void
+    {
+        $this->requestPipeline = clone $this->requestPipeline;
+        $this->responsePipeline = clone $this->responsePipeline;
+        $this->fatalPipeline = clone $this->fatalPipeline;
+    }
+
     /**
      * Add a middleware before the request is sent
      *

src/Http/Request.php

@@ -59,6 +59,36 @@ public function getMethod(): Method
         return $this->method;
     }
 
+    /**
+     * Ensure cloned requests do not share mutable object state (query, headers, etc.).
+     *
+     * Without this, a shallow clone reuses the same {@see \Saloon\Repositories\ArrayStore}
+     * instances when they were initialized before cloning, which breaks concurrent pools
+     * (e.g. paginated requests mutating the same query bag).
+     */
+    public function __clone(): void
+    {
+        if (isset($this->query)) {
+            $this->query = clone $this->query;
+        }
+
+        if (isset($this->headers)) {
+            $this->headers = clone $this->headers;
+        }
+
+        if (isset($this->config)) {
+            $this->config = clone $this->config;
+        }
+
+        if (isset($this->delay)) {
+            $this->delay = clone $this->delay;
+        }
+
+        if (isset($this->middlewarePipeline)) {
+            $this->middlewarePipeline = clone $this->middlewarePipeline;
+        }
+    }
+
     /**
      * Define the endpoint for the request.
      */

tests/Unit/RequestCloneTest.php

@@ -0,0 +1,86 @@
+<?php
+
+declare(strict_types=1);
+
+use Saloon\Http\Response;
+use Saloon\Http\Faking\MockClient;
+use Saloon\Http\Faking\MockResponse;
+use Saloon\Tests\Fixtures\Requests\UserRequest;
+use Saloon\Tests\Fixtures\Connectors\TestConnector;
+
+test('cloning a request after query() is initialized gives independent query bags', function () {
+    $original = new UserRequest;
+    $original->query()->add('key', 'value');
+
+    $a = clone $original;
+    $b = clone $original;
+
+    $a->query()->add('page', 1);
+    $b->query()->add('page', 2);
+
+    expect($a->query()->get('page'))->toBe(1);
+    expect($b->query()->get('page'))->toBe(2);
+    expect($original->query()->get('page'))->toBeNull();
+    expect($original->query()->get('key'))->toBe('value');
+});
+
+test('cloning a request after headers config and delay are initialized gives independent stores', function () {
+    $original = new UserRequest;
+    $original->headers()->add('X-Test', 'one');
+    $original->config()->add('timeout', 10);
+    $original->delay()->set(5);
+
+    $clone = clone $original;
+
+    $clone->headers()->add('X-Test', 'two');
+    $clone->config()->add('timeout', 20);
+    $clone->delay()->set(15);
+
+    expect($original->headers()->get('X-Test'))->toBe('one');
+    expect($clone->headers()->get('X-Test'))->toBe('two');
+    expect($original->config()->get('timeout'))->toBe(10);
+    expect($clone->config()->get('timeout'))->toBe(20);
+    expect($original->delay()->get())->toBe(5);
+    expect($clone->delay()->get())->toBe(15);
+});
+
+test('cloning a request after middleware is initialized gives independent pipelines', function () {
+    $original = new UserRequest;
+    $original->middleware()->onResponse(static fn (Response $response): Response => $response);
+
+    $clone = clone $original;
+
+    expect($original->middleware())->not->toBe($clone->middleware());
+});
+
+test('concurrent pool sends with cloned requests do not share query mutation', function () {
+    $sequence = [];
+    for ($i = 0; $i < 10; $i++) {
+        $sequence[] = MockResponse::make(['ok' => true]);
+    }
+
+    $connector = new TestConnector;
+    $connector->withMockClient(new MockClient($sequence));
+
+    $base = new UserRequest;
+    $base->query()->add('key', 'value');
+
+    $requests = [];
+    for ($i = 1; $i <= 10; $i++) {
+        $r = clone $base;
+        $r->query()->add('page', $i);
+        $requests[] = $r;
+    }
+
+    $pagesSeen = [];
+
+    $pool = $connector->pool($requests, 5);
+    $pool->withResponseHandler(function (Response $response) use (&$pagesSeen): void {
+        $pagesSeen[] = (int) $response->getRequest()->query()->get('page');
+    });
+
+    $pool->send()->wait();
+
+    expect($pagesSeen)->toHaveCount(10);
+    expect(array_unique($pagesSeen))->toHaveCount(10);
+});