Bug in phpdbg8.3 (also 8.1 and 8.2) echo output - trimmed at NULL byte (?)

[smuuf]

Description

The following code:

<?php

echo "hello\0world";

✅ Results in this output when executed with php8.3 (also php8.2 and php8.1 and php8.0):

helloworld

❌ But results in this output when executed with phpdbg8.3 (also phpdbg8.2 and phpdbg8.1):

hello

And I expected this output from phpdbg8.* instead:

helloworld

❔Interesting thing is that phpdbg8.0 output is correct:

helloworld

... so the change in behavior seems to be somewhere in between latest 8.0.* and 8.1.

Steps to reproduce with docker

php8.0 ✅

docker run -it php:8.0-cli bash -c 'php --version; echo; echo "<?php echo \"hello\" . chr(0) . \"world\";" > lol.php; echo -n "php .|"; php lol.php; echo -en "|.\nphpdbg .|"; phpdbg -qrrb lol.php; echo "|."'

PHP 8.0.30 (cli) (built: Nov 21 2023 16:10:15) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.30, Copyright (c) Zend Technologies

php .|helloworld|.
phpdbg .|helloworld|.

php8.1 ❌

docker run -it php:8.1-cli bash -c 'php --version; echo; echo "<?php echo \"hello\" . chr(0) . \"world\";" > lol.php; echo -n "php .|"; php lol.php; echo -en "|.\nphpdbg .|"; phpdbg -qrrb lol.php; echo "|."'

PHP 8.1.29 (cli) (built: Jun 13 2024 03:00:05) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.1.29, Copyright (c) Zend Technologies

php .|helloworld|.
phpdbg .|hello|.

php8.2 ❌

docker run -it php:8.2-cli bash -c 'php --version; echo; echo "<?php echo \"hello\" . chr(0) . \"world\";" > lol.php; echo -n "php .|"; php lol.php; echo -en "|.\nphpdbg .|"; phpdbg -qrrb lol.php; echo "|."'

PHP 8.2.20 (cli) (built: Jun 13 2024 02:30:07) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.2.20, Copyright (c) Zend Technologies

php .|helloworld|.
phpdbg .|hello|.

php8.3 ❌

docker run -it php:8.3-cli bash -c 'php --version; echo; echo "<?php echo \"hello\" . chr(0) . \"world\";" > lol.php; echo -n "php .|"; php lol.php; echo -en "|.\nphpdbg .|"; phpdbg -qrrb lol.php; echo "|."'

PHP 8.3.8 (cli) (built: Jun 13 2024 01:58:54) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.3.8, Copyright (c) Zend Technologies

php .|helloworld|.
phpdbg .|hello|.

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PHP Version

PHP 8,1-8.3

Operating System

WSL1, WSL2 and also bare Ubuntu

[nielsdos]

Regressed in 6318040