fix: populateGlobals for JSON and XML body format

[michalsn]

Description
This PR fixes a bug in the populateGlobals() method in the FeatureTestTrait class.
If the body format is set to json or xml, we should not use setGlobal() for post requests.
The POST array should be empty since the data is stored in the raw input stream.

I think this is the proper way to solve the problem, although if anyone sees any issues, feedback is welcome (as always).

Closes #9204

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[neznaika0]

I think there is a potential error in fetchGlobal() - it does not understand the numeric keys $_GET[0]['one'] = 1

[neznaika0]

In any case, $_GET is set to $request->setGlobal('get', $get), which means $_REQUEST must have values from $_GET. Your change is not necessary.

See other test:

diff --git a/system/HTTP/RequestTrait.php b/system/HTTP/RequestTrait.php
index 43a4f23a0e..a47d4c7a69 100644
--- a/system/HTTP/RequestTrait.php
+++ b/system/HTTP/RequestTrait.php
@@ -290,7 +290,7 @@ trait RequestTrait
         }
 
         // Does the index contain array notation?
-        if (($count = preg_match_all('/(?:^[^\[]+)|\[[^]]*\]/', $index, $matches)) > 1) {
+        if (is_string($index) && ($count = preg_match_all('/(?:^[^\[]+)|\[[^]]*\]/', $index, $matches)) > 1) {
             $value = $this->globals[$name];
 
             for ($i = 0; $i < $count; $i++) {
diff --git a/tests/system/HTTP/RequestTest.php b/tests/system/HTTP/RequestTest.php
index e2073268d7..2205f29dfe 100644
--- a/tests/system/HTTP/RequestTest.php
+++ b/tests/system/HTTP/RequestTest.php
@@ -196,6 +196,21 @@ final class RequestTest extends CIUnitTestCase
         $this->assertCount(2, $result['ANNOUNCEMENTS']);
     }
 
+    public function testFetchGlobalReturnsWithListValues(): void
+    {
+        $post = [
+            ['foo' => 0],
+            ['bar' => 1],
+            ['baz' => 2],
+        ];
+
+        $this->request->setGlobal('post', $post);
+        $result = $this->request->fetchGlobal('post');
+
+        $this->assertIsList($result);
+        $this->assertSame($post, $result);
+    }
+
     public function testFetchGlobalWithArrayTop(): void
     {
         $post = [

[michalsn]

@neznaika0 That makes sense. I haven't seen the real problem. Nice!

Would you like to send a PR?