Consider removing default -n flag (use system php.ini by default)

[dg]

Tester runs PHP with -n flag by default, ignoring php.ini to ensure a clean, reproducible environment. Users who need php.ini must explicitly use -C or -c path/to/php.ini.

The idea was to provide a consistent, isolated environment where all configuration is explicitly provided by the test suite, avoiding "works on my machine" issues caused by different php.ini settings.

In practice, this approach doesn't work well on Linux because:

1. Extensions like intl, fileinfo, etc. are installed system-wide and require extension_dir to be set correctly
2. There's no practical way to bundle these extensions with the test suite
3. As a result, almost everyone ends up using -C anyway
4. Tests fail with confusing errors about "missing extensions" when -C is forgotten

Proposal:
Remove the default -n behavior - let Tester use system php.ini by default (equivalent to current -C).

Users who want isolated environment can still use explicit -c flag.

[milo]

I think this is a good idea. Only I would preserve possibility to pass -n explicitly or pass -n together with -c php.ini automatically if used.

It's not well documented but if -c ... is passed, it does not replace all loaded INI files from "Scan this dir for additional .ini files". Try php -c a.ini -r 'phpinfo();' | more (see output from my dev Debian machine below). Without -n environment is not clean and as a side effect tests will be slowed down by one order of magnitude (in my case).

$ php -c a.ini -r 'phpinfo();' | more
...
Configuration File (php.ini) Path => /etc/php/8.4/cli
Loaded Configuration File => /home/milo/php/a.ini
Scan this dir for additional .ini files => /etc/php/8.4/cli/conf.d
Additional .ini files parsed => /etc/php/8.4/cli/conf.d/10-mysqlnd.ini,
/etc/php/8.4/cli/conf.d/10-opcache.ini,
/etc/php/8.4/cli/conf.d/10-pdo.ini,
/etc/php/8.4/cli/conf.d/15-xml.ini,
/etc/php/8.4/cli/conf.d/20-calendar.ini,
/etc/php/8.4/cli/conf.d/20-ctype.ini,
/etc/php/8.4/cli/conf.d/20-curl.ini,
/etc/php/8.4/cli/conf.d/20-dom.ini,
/etc/php/8.4/cli/conf.d/20-exif.ini,
/etc/php/8.4/cli/conf.d/20-ffi.ini,
/etc/php/8.4/cli/conf.d/20-fileinfo.ini,
/etc/php/8.4/cli/conf.d/20-ftp.ini,
/etc/php/8.4/cli/conf.d/20-gd.ini,
/etc/php/8.4/cli/conf.d/20-gettext.ini,
/etc/php/8.4/cli/conf.d/20-iconv.ini,
/etc/php/8.4/cli/conf.d/20-ldap.ini,
/etc/php/8.4/cli/conf.d/20-mbstring.ini,
/etc/php/8.4/cli/conf.d/20-mysqli.ini,
/etc/php/8.4/cli/conf.d/20-pdo_mysql.ini,
/etc/php/8.4/cli/conf.d/20-pdo_pgsql.ini,
/etc/php/8.4/cli/conf.d/20-pgsql.ini,
/etc/php/8.4/cli/conf.d/20-phar.ini,
/etc/php/8.4/cli/conf.d/20-posix.ini,
/etc/php/8.4/cli/conf.d/20-readline.ini,
/etc/php/8.4/cli/conf.d/20-shmop.ini,
/etc/php/8.4/cli/conf.d/20-simplexml.ini,
/etc/php/8.4/cli/conf.d/20-sockets.ini,
/etc/php/8.4/cli/conf.d/20-sqlsrv.ini,
/etc/php/8.4/cli/conf.d/20-sysvmsg.ini,
/etc/php/8.4/cli/conf.d/20-sysvsem.ini,
/etc/php/8.4/cli/conf.d/20-sysvshm.ini,
/etc/php/8.4/cli/conf.d/20-tokenizer.ini,
/etc/php/8.4/cli/conf.d/20-xmlreader.ini,
/etc/php/8.4/cli/conf.d/20-xmlwriter.ini,
/etc/php/8.4/cli/conf.d/20-xsl.ini,
/etc/php/8.4/cli/conf.d/20-zip.ini
...

[KminekMatej]

I agree that most users uses at least -C or -c parameter anyway, which is plus to get rid of -n parameter in default.

But there probably are some testers who rely on the fact that their code runs without any extensions and could be suprised by change of default behaviour. Since adding -C or -c only extends possibilities of PHP, it shouldnt be considered as a bc break, but definitely change worth mentioning.

As @milo said earlier, I also vote to keep the -n parameter available for such users. But since this parameter is not documented, with this change it may be neccessary to document it

[dg]

So the plan is:

Current behavior:

• Default: tests ran with -n (no php.ini)
• Displayed message "Note: No php.ini is used."
• -C: suppressed -n, used system php.ini
• -c <path>: used -n -c <path>
• -c <path> -C: used -c <path>

New behavior:

• Default: tests run with system php.ini (no -n)
• -C: has no effect (same as before) ✓
• -c <path>: uses -n -c <path> (same as before) ✓
• -c <path> -C: uses just -c <path> (same as before) ✓

Potential risk: Running without parameters now uses system php.ini instead of -n. This may affect tests that relied on a clean environment without extensions from system ini.

[KminekMatej]

Ten potential risk je imho dost marginální. To by mohlo nastat jen v situaci kdy někdo definuje funkce v globálním namespacu které se jmenují stejně jako v nějakém extension. Teď by to použilo tu funkci v extension - nebo by to možná rovnou zařvalo

[milo]

@dg Agree with the new bahavior. It's more friendly.