conditional install dirs vs. mkdir_p

[Ralf Corsepius]

Given a Makefile.am, that conditionally installs headers to a directory
defined inside of the condition, similar to this:

if HAVE_FOO
include_foodir = $(includedir)/foo
include_foo_HEADERS = foo.h
endif

If HAVE_FOO is false, with automake-1.8 this happens:

make install
make[1]: Entering directory `/tmp/autobug'
make[1]: Nothing to be done for `install-exec-am'.
mkdir -m 0755 -p --
mkdir: too few arguments
Try `mkdir --help' for more information.
make[1]: *** [install-include_fooHEADERS] Error 1
make[1]: Leaving directory `/tmp/autobug'

-> mkdir -p is invoked with an empty directory and chokes.

With automake-1.7.9 this used to work:

make install
make[1]: Entering directory `/tmp/autobug'
make[1]: Nothing to be done for `install-exec-am'.
/bin/sh ./mkinstalldirs
make[1]: Leaving directory `/tmp/autocrap'

-> Here, mkinstalldirs is invoked with an empty directory, but it
doesn't choke.

I haven't checked if this bug might have been fixed in automake-1.8b.

Ralf