Order of Filter Types with the same values

[Jason Gionta <jjgionta@xxxxxxxx>]

Hi everyone,

I have been looking over the httpd source looking for how the filter types are order when they are registered with the same filter type value.

For example, http_core.c registers HTTP_HEADER, HTTP_OUTERROR, and BYTERANGE (in this order) with a filter type of AP_FTYPE_PROTOCOL.  In this manner, they all have the same value for FTYPE so I assume they will keep this order or will be reversed.   However, when the filter chain is generated for a request, the filter chain is generated in the order BYTERANGE, HTTP_HEADER, and HTTP_OUTERROR.  

Similarly, the filter CONTENT_LENGTH has the AP_FTYPE_PROTOCOL and it some how gets ordered between BYTERANGE and HTTP_HEADER.

Can someone shed light on this?  Documentation does not discuss this ordering mechanism and it is not readily apparent how this ordering is being accomplished.

Thanks,

Jason