Undefined array key "SCRIPT_NAME" in wp_fix_server_vars()

[mcjambi]

My log file is increasing size day by day with this bug:
[16-Sep-2021 21:37:01 UTC] PHP Warning: Undefined array key "SCRIPT_NAME" in /home/rntlckly/public_html/wp-includes/load.php on line 79

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PHP 8.x
Wordpress 5.8.1

[costdev]

Hi @mcjambi,

This issue is usually related to cron jobs, or server configuration, such as when running with fastcgi, etc. ​This support thread may be relevant to you.

If you are unable to resolve the issue from that thread, please create a new thread in ​the WordPress Support forums, providing some information about your server configuration and whether this is occurring when accessing WordPress via browser or if you're using another method.

[SergeyBiryukov]

Hi there, welcome back to WordPress Trac! Thanks for the report.

It looks like this code was introduced in [3034] and adjusted in [3069]. Changing the Version field accordingly.

[audrasjb]

Patch refreshed against trunk for 5.9

[hellofromTonya]

Assigning to me to check behavior of the PHP native function (for PHP 8.1) and if cool, get it committed.

[hellofromTonya]

Noting: If the key doesn't exist, the error depends upon the PHP version:

• PHP 8.0+ throws a warning
• PHP 8.1 also throws a deprecation notice

  Deprecated: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
  

• PHP 9 will likely be a fatal error

See it in action: ​https://3v4l.org/aJ2kX

[hellofromTonya]

In 52144:

Bootstrap/Load: Check $_SERVER['SCRIPT_NAME'] exists before passing to strpos() in wp_fix_server_vars().

If SCRIPT_NAME' does not exist (which can happen in cron jobs), the following happens:

• PHP 8.1+:
  • Warning: Undefined array key "SCRIPT_NAME"
  • Deprecated: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
• PHP 8.0: Warning: Undefined array key "SCRIPT_NAME"
• PHP 5.6-7.4: No warning or notice

This commit checks if the key exists before passing it to strpos(). This resolves the warning, notice, and future error.

Follow-up to [3034], [3069], [12732].

Props audrasjb, costdev, hellofromTonya, karpstrucking, mcjambi, sergeybiryukov.
Fixes #54142.

[hellofromTonya]

Thank you everyone for contributing! This fix will ship in 5.9.