`DOCUMENT_ROOT` from environment in cli is not propagated to $_SERVER['DOCUMENT_ROOT']

[ivan-u7n]

Description

The following code:

DOCUMENT_ROOT=/test php -r 'var_dump($_SERVER["DOCUMENT_ROOT"]);'

Resulted in this output:

string(0) ""

But I expected this output instead:

string(5) "/test"

with a file the out is the same
I think the culprit is

php-src/sapi/cli/php_cli.c

Line 344 in 42f994c

if (sapi_module.input_filter(PARSE_SERVER, "DOCUMENT_ROOT", &docroot, len, &len)) {

as the only mention of DOCUMENT_ROOT for php-cli

PHP Version

PHP 8.4.15 (cli) (built: Nov 20 2025 19:00:52) (NTS)
Copyright (c) The PHP Group
Built by Debian
Zend Engine v4.4.15, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.15, Copyright (c), by Zend Technologies

Operating System

No response

[iluuu1994]

Hi @ivan-u7n. DOCUMENT_ROOT is just always declared as an empty string in CLI. This could be adjusted to use the value of the env var as it is for CGI/FPM. But I would classify that as a feature request.

[ivan-u7n]

hi, @iluuu1994,
in my opinion it is still a bug, because there is nothing special about DOCUMENT_ROOT (as opposed to SCRIPT_FILENAME, PHP_SELF and so on from the thereabouts of setting DOCUMENT_ROOT to empty string)

however, I agree that having empty DOCUMENT_ROOT is usefull, but only as a fallback when DOCUMENT_ROOT has not been already set via environment

and that is my resolution for this bug is something akin to:

	len = strlen("DOCUMENT_ROOT");
	if (track_vars_array && Z_TYPE_P(track_vars_array) == IS_ARRAY && !zend_symtable_str_exists(track_vars_array, "DOCUMENT_ROOT", len)) {
		len = 0U;
		if (ZVAL_TYPE(track_vars_array) sapi_module.input_filter(PARSE_SERVER, "DOCUMENT_ROOT", &docroot, len, &len)) {
			php_register_variable("DOCUMENT_ROOT", docroot, track_vars_array);
		}
	}

otherwise it is impossible to write scripts relative to some common root both for web and for cli; and DOCUMENT_ROOT seems the natural root for that case