Description:
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When running the PHP internal web server, the location of the router script affects the output of the PHP_SELF value in an unusual way.

If I run PHP from the folder with the script in:

$ php -S 0:8080 index.php

And then call http://localhost:8080/, the value for PHP_SELF is `/index.php`. If I run the script from a parent directory (or any other location that differs from the script), e.g.:

$ php -S 0:8080 src/index.php

The value for PHP_SELF when request http://localhost:8080/foo/bar will be `/foo/bar`.

I'm not certain if this behaviour is intentional or not, but if it is, why is it this way? We noticed this issue because it breaks a lot of popular routing libraries as they strip the content of PHP_SELF from the variable they discern the path from, so it fails to route requests correctly.


Test script:
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<?php echo $_SERVER['PHP_SELF'];

Expected result:
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Expect the PHP_SELF value to always provide a path to the script, not change between this and the web requested path.