tar-ustar documentation improvements

[Simon Josefsson]

I tried to use a long filename with tar-ustar, but it didn't work.
The GNU Tar documentation has this to say about ustar:

       1. The maximum length of a file name is limited to 256
          characters, provided that the filename can be split at
          directory separator in two parts, first of them being at most
          155 bytes long. So, in most cases the maximum file name
          length will be shorter than 256 characters.

So it seems the current Automake documentation is too optimistic.
What do you think of the patch below?

PS. I'm using "tar-pax" now.  Let's see if it works...

Thanks,
Simon

2004-07-08  Simon Josefsson  <address@hidden>

        * doc/automake.texi (Options): Improve ustar file name length
        discussion.  Reference tar manual.

Index: automake.texi
===================================================================
RCS file: /cvs/automake/automake/doc/automake.texi,v
retrieving revision 1.39
diff -u -p -u -w -r1.39 automake.texi
--- automake.texi       5 Jul 2004 07:07:05 -0000       1.39
+++ automake.texi       8 Jul 2004 15:25:22 -0000
@@ -6006,11 +6006,14 @@ directories.  When using this format, co
 
 @code{tar-ustar} selects the ustar format defined by POSIX
 1003.1-1988.  This format is believed to be old enough to be portable.
-It fully supports directories, and stores filenames with up to 255
-characters.  However you may run against broken tar implementations
-that incorrectly handle filenames longer than 99 characters (please
-report them to @email{bug-automake@@gnu.org} so we can document this
-accurately).
+It fully supports empty directories.  It can stores filenames with up
+to 256 characters, provided that the filename can be split at
+directory separator in two parts, first of them being at most 155
+bytes long. So, in most cases the maximum file name length will be
+shorter than 256 characters.  However you may run against broken tar
+implementations that incorrectly handle filenames longer than 99
+characters (please report them to @email{bug-automake@@gnu.org} so we
+can document this accurately).
 
 @code{tar-pax} selects the new pax interchange format defined by POSIX
 1003.1-2001.  It does not limit the length of filenames.  However,
@@ -6019,6 +6022,9 @@ packages which target only very modern p
 change the pax format in an upward-compatible way, so this option may
 refer to a more recent version in the future.
 
address@hidden, , Controlling the Archive Format, tar, GNU Tar}, for
+further discussion about tar formats.
+
 @code{configure} knows several ways to construct these formats.  It
 will not abort if it cannot find a tool up to the task (so that the
 package can still be built), but @code{make dist} will fail.