Bug: output buffer

[iRedds]

PHP Version

7.4

CodeIgniter4 Version

all

CodeIgniter4 Installation Method

Git

Which operating systems have you tested for this bug?

Windows

Which server did you use?

apache

Database

No response

What happened?

The application starts monitoring the buffer in the CodeIgniter::tryToRouteIt() method.

CodeIgniter4/system/CodeIgniter.php

Line 813 in 42b174f

ob_start();

For a correct response, and in case of a 404 error, if a custom handler is defined, the CodeIgniter::gatherOutput() method is called. In which we are trying to complete the monitoring of the buffer.

CodeIgniter4/system/CodeIgniter.php

Lines 1009 to 1014 in 42b174f

	$this->output = ob_get_contents();
	// If buffering is not null.
	// Clean (erase) the output buffer and turn off output buffering
	if (ob_get_length()) {
	ob_end_clean();
	}

But this code only works if something was passed to the buffer, such as using echo.
If nothing has been written to the buffer, then buffer monitoring is not disabled.
Also, if the ob_start() function has been called multiple times while the application is running, then ob_end_clean() will only terminate the last one.

Steps to Reproduce

namespace CodeIgniter;

use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\Mock\MockCodeIgniter;
use Config\App;

/**
 * @internal
 */
final class StepsToReproduceTest extends CIUnitTestCase
{
    public function testOB()
    {
        $actual['phpunit'] = ob_get_level();

        ob_start();

        $actual['beforeApp'] = ob_get_level();

        (new MockCodeIgniter(new App()))->run();

        $actual['afterApp'] = ob_get_level();

        ob_get_clean();

        $this->assertSame(
            [
                'phpunit' => 1,
                'beforeApp' => 2,
                'afterApp' => 2,
            ],
            $actual
        );
    }
}

1) CodeIgniter\StepsToReproduceTest::testOB
Failed asserting that two arrays are identical.
--- Expected
+++ Actual
@@ @@
 Array &0 (
     'phpunit' => 1
     'beforeApp' => 2
-    'afterApp' => 2
+    'afterApp' => 3
 )

Expected Output

Normalize work on the buffer.

Anything else?

In the \CodeIgniter\Debug\Exceptions class, buffer monitoring also ends incorrectly.

CodeIgniter4/system/Debug/Exceptions.php

Lines 273 to 275 in 42b174f

	if (ob_get_level() > $this->ob_level + 1) {
	ob_end_clean();
	}

class OBuffer
{
    protected ?int $level;

    public function start(): void
    {
        $this->level = ob_get_level();
        ob_start();
    }

    public function getClean(): string
    {
        $content = '';

        while (ob_get_level() > $this->level) {
            $content .= ob_get_contents();
            ob_end_clean();
        }

        return $content;
    }
}

This is an example of code that, in my opinion, will solve the buffer monitoring problem if you replace the ob_ function calls in the CodeIgniter::tryToRouteIt() and CodeIgniter::gatherOutput() methods with the appropriate methods class.
It will also remove redundant code.

CodeIgniter4/system/CodeIgniter.php

Lines 1018 to 1022 in 42b174f

	if (ENVIRONMENT !== 'testing') {
	while (ob_get_level() > 0) {
	ob_end_clean();
	}
	}

[kenjis]

Closed by #7500