[libvirt] How to trigger autoheader after configure.ac changes?

[TJ]

I'm currently adding support for running a DHCP relay daemon instead of using dnsmasq for DHCP.

Everything is looking good but I've stumbled on one issue.

I've added a new variable to 'configure.a' (DHCPRELAY) but found that 'autogen.sh' doesn't call
'autoheader' to remake 'config.h.in' so it contains the definition of DHCPRELAY for the compiler.

Reading 'autogen.sh' and 'bootstrap' I can see convoluted functionality but can't figure out
what the recommended best practice would be in terms of generating the new 'config.h.in'.

If I call 'autoheader' manually the definition is added correctly.

Should I just do that and then add the changed 'config.h.in' to the commit that introduces the
new definition?