automake/31: include dir always created even when conditional

["Andrew S. Townley" <atownley at informix dot com>]

>Number:         31
>Category:       automake
>Synopsis:       include dir always created even when conditional
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    tromey
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Nov 20 17:21:00 PST 1999
>Closed-Date:
>Last-Modified:
>Originator:     Andrew S. Townley
>Release:        current cvs
>Organization:
>Environment:

>Description:
I looked through the archives and have spent a considerable amount of
time today trying to figure out if there was a way to keep
$(distdir)/include from being created.  It looks like that no matter
what, the install-includeHEADERS generated target will make
$(DESTDIR)$(includedir), even if there are not any files in
$(include_HEADERS).

Is there a way to prevent the creation of the directoy?  What I'm trying
to do is support an option to configure that will determine if the
header files are installed (the default is no).  So, in my Makefile.am,
I have something like:

hdrs = a.h b.h c.h

if INSTALLHDRS
include_HEADERS = $(hdrs)
else
noinst_HEADERS = $(hdrs)
endif

So, what happens if I don't specify --enable-install-headers is an empty
include directory is created.

Any ideas or better ways to accomplish this are welcome.  Oh, I forgot
to mention that all the files, source and headers, are in the same
directory.
>How-To-Repeat:

>Fix:
One fix would be to make rules have the same condition
as the variables which trigger them.
>Release-Note:
>Audit-Trail:
>Unformatted: