aclocal: don't create /usr/share/aclocal as empty

Related to automake bug#10791.

Since automake 1.11.2, aclocal no longer succeeds if the system
acdir '${datadir}/aclocal' (i.e., "/usr/share/aclocal" when
${prefix} is "/usr") does not exist.  So we now have a directory
*installed empty by default*, but whose existence is required by
aclocal in order for it to function at all.  This might be
confusing, and sounds like asking for trouble in the long term.

So we now also install a simple README file in that directory,
which briefly explains its purpose and warn that its existence
is required by the normal aclocal functioning.

* m4/acdir/README: New file.
* m4/Makefile.am (dist_system_ac_DATA): Add it.
* m4/acdir/.placeholder: Delete, no more needed.
* m4/Makefile.am (EXTRA_DIST): Remove it.
* THANKS: Update.

diff --git a/THANKS b/THANKS
index 36f8f4b..7b7c9df 100644 (file)
--- a/THANKS
+++ b/THANKS
@@ -360,6 +360,7 @@ Thomas Tanner               tanner@ffii.org
 Toralf Förster                toralf.foerster@gmx.de
 Tim Goodwin            tjg@star.le.ac.uk
 Tim Mooney             mooney@dogbert.cc.ndsu.NoDak.edu
+Tim Retout             diocles@debian.org
 Tim Rice               tim@multitalents.net
 Tim Van Holder         tim.van.holder@pandora.be
 Toshio Kuratomi                toshio@tiki-lounge.com

diff --git a/m4/Makefile.am b/m4/Makefile.am
index 29e5e05..572fca7 100644 (file)
--- a/m4/Makefile.am
+++ b/m4/Makefile.am
@@ -55,10 +55,9 @@ tar.m4 \
 upc.m4 \
 vala.m4
 
-# So that $(system_acdir) will be created by "make install".
-dist_system_ac_DATA =
+dist_system_ac_DATA = acdir/README
 
-EXTRA_DIST = acdir/.placeholder amversion.in
+EXTRA_DIST = amversion.in
 
 # We build amversion.m4 here, instead of from config.status,
 # because config.status is rerun each time one of configure's

diff --git a/m4/acdir/.placeholder b/m4/acdir/.placeholder
deleted file mode 100644 (file)
index 8dd7f67..0000000
--- a/m4/acdir/.placeholder
+++ /dev/null
@@ -1,2 +0,0 @@
-This file is here only to ensure the directory containing it exists
-in the git repository, and goes in the distribution tarball.

diff --git a/m4/acdir/README b/m4/acdir/README
new file mode 100644 (file)
index 0000000..c2bf903
--- /dev/null
+++ b/m4/acdir/README
@@ -0,0 +1,9 @@
+This directory is where .m4 files providing third-party autoconf
+macros can be placed to be automatically found by the aclocal(1)
+program.
+
+The .m4 files placed here could be shared among different versions
+of aclocal, so be careful.
+
+Even no actual .m4 files are present, this directory is required
+in order for aclocal to work properly.  Please do not remove it.