avoid buggy AIX 5.3 cp -R.

[Ralf Wildenhues]

automake/tests/fn99{,subdir}.test have been long-time failures on
AIX 5.[123], but not 6.1 or newer (and IIRC not 4.3.3 either):
http://autobuild.josefsson.org/automake/log-201101181921915482000.txt

| + make distcheck
|         make  dist-gzip am__post_remove_distdir='@:'
|         { test ! -d "fn99-1.0"  || { find "fn99-1.0" -type d ! -perm -200 
-exec chmod u+w {} ';'  && rm -fr "fn99-1.0"; }; }
|         test -d "fn99-1.0" || mkdir "fn99-1.0"
| cp: 8???: A file or directory in the path name does not exist.
| make: 1254-004 The error code from the last command is 1.

I finally got myself to look at this a bit, and playing around with
various directory depths and whether there are files in them, I can only
come to the conclusion that this system's cp -R is simply unusable as it
corrupts its memory depending on the source tree layout.  I've even got
it to dump core.

Any reasons against these two patches, for Autoconf master and Automake
maint?

It might be possible to rework the distdir rule to use maybe
  tar cBf - files | (cd $(distdir) && tar xf -)

but that opens up its own set of problems (are ACLs copied? is the
sub-second time stamp handling the same as that of cp?) I'm not eager
to pursue this unless we see a real-life bug report from somebody who
needs it to work on AIX.

Thanks,
Ralf

    docs: do not use AIX 5.3 cp -R.
    
    * doc/autoconf.texi (Limitations of Usual Tools): Document one
    instance of the cp -R bug on AIX 5.3.  This seems to have been
    fixed in 6.1 and newer releases.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 4cb3a8c..eee4ba7 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -18065,7 +18065,16 @@ Avoid the @option{-r} option, since Posix 1003.1-2004 
marks it as
 obsolescent and its behavior on special files is implementation-defined.
 Use @option{-R} instead.  On GNU hosts the two options
 are equivalent, but on Solaris hosts (for example) @code{cp -r}
-reads from pipes instead of replicating them.
+reads from pipes instead of replicating them.  AIX 5.3 @code{cp -R} may
+corrupt its own memory with some directory hierarchies and error out or
+dump core:
+
address@hidden
address@hidden -p 12345678/12345678/12345678/12345678}
address@hidden 12345678/12345678/x}
address@hidden -R 12345678 t}
+cp: 0653-440 12345678/12345678/: name too long.
address@hidden example
 
 Some @command{cp} implementations (e.g., BSD/OS 4.2) do not allow
 trailing slashes at the end of nonexistent destination directories.  To



    tests: avoid fn99*.test failures due to buggy AIX 5.3 cp -R.
    
    * tests/fn99.test, tests/fn99subdir.test: Skip if an initial
    `cp -R' of the subdir tree already fails; AIX 5.3 cp messes
    up its internal memory when copying this tree.

diff --git a/tests/fn99.test b/tests/fn99.test
index e80d09f..c2afd2e 100755
--- a/tests/fn99.test
+++ b/tests/fn99.test
@@ -32,6 +32,9 @@ do
   touch x
 done) || Exit 77
 
+# AIX 5.3 `cp -R' is too buggy for `make dist'.
+cp -R 12345678 t || Exit 77
+
 $ACLOCAL
 $AUTOCONF
 $AUTOMAKE
diff --git a/tests/fn99subdir.test b/tests/fn99subdir.test
index 0f05b5a..a040e58 100755
--- a/tests/fn99subdir.test
+++ b/tests/fn99subdir.test
@@ -53,6 +53,9 @@ do
   touch x
 done)
 
+# AIX 5.3 `cp -R' is too buggy for `make dist'.
+cp -R ${subdirname} t || Exit 77
+
 for init_dir in ${subdirname} .; do
        (
                cd ${init_dir} || Exit 1