In case one of the pre_connection hooks causes the hook run to stop by an error

the pre_connection hook of the core module maybe did not run
(it is APR_HOOK_REALLY_LAST) and hence we missed to

- Put the socket in c->conn_config
- Setup core output and input filters
- Set socket options and timeouts

For calls of ap_run_pre_connection where this matters create a wrapper named
ap_pre_connection that ensures that this happens.

* include/ap_mmn.h: Bump minor version as we added new ap_pre_connection
  function.

* include/http_connection.h: Declare ap_pre_connection prototype.

* server/connection.c: Make use of ap_pre_connection in ap_process_connection.

* server/core.c: Implement ap_pre_connection.

* server/mpm/event/event.c: Make use of ap_pre_connection.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1893497 13f79535-47bb-0310-9956-ffa450edef68

include/http_connection.h

@@ -135,6 +135,21 @@ AP_DECLARE_HOOK(int,process_connection,(conn_rec *c))
  */
 AP_DECLARE_HOOK(int,pre_close_connection,(conn_rec *c))
 
+/**
+ * This is a wrapper around ap_run_pre_connection. In case that
+ * ap_run_pre_connection returns an error it marks the connection as
+ * aborted and ensures that the basic connection setup normally done
+ * by the core module is done in case it was not done so far.
+ * @param c The connection on which the request has been received.
+ *          Same as for the pre_connection hook.
+ * @param csd The mechanism on which this connection is to be read.
+ *            Most times this will be a socket, but it is up to the module
+ *            that accepts the request to determine the exact type.
+ *            Same as for the pre_connection hook.
+ * @return The result of ap_run_pre_connection
+ */
+AP_DECLARE(int) ap_pre_connection(conn_rec *c, void *csd);
+
 /**
  * Create a new server/incoming or client/outgoing/proxy connection
  * @param p The pool from which to allocate the connection record