Description:
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chdir() seems to not use streams to validate the passed path. When one defines a custom wrapper for the file:// scheme, it can be problematic.

For example, my custom file:// wrapper is acting like a root jail, "/" being mapped to some directory on disk. This was needed to prevent XML documents xinclude()'ing stuffs outside of the authorized directory, among other things. It works very well except that I'm forced to set the CWD to "/" as other jailed directories are reported as "not found" by PHP.

Example:

If "/srv/www/jail" is the root jail "/srv/www/jail/data/file.xml" is accessible within the script under the path "/data/file.xml". There I have no way to set the CWD to /data if the real on-disk "/data" path doesn't exist.

Maybe this behavior should not change for some reason, but this is a use case where it would be nice.