How to Restrict an Apache Module (Handler) to a Virtual Host (vhost)
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I have an apache module which uses the `ap_hook_post_read_request` hook to perform an internal redirect when certain conditions are met. I would like to restrict this handler to a single virtual host but currently it fires on all virtual hosts (there are many). The httpd.conf configuration is limited to the `LoadModule` directive. I've tried using `SetHandler handlername` in the vhost and `SetHandler None` in the main config but the handler is still invoked on requests to other vhosts. The module also registers the `ap_register_output_filter` hook but the  output filter does not perform any action other than removing itself and passing control onwards. 