Docs for --preserve option

[Ángel González]

Hello everybody,

Failing to understand --preserve option *after reading the man page*, I
hope to help
improving the docs so future users won't hit the same builder.

The specific section at cp --help (from which cp man is generated) is:
> --preserve[=ATTR_LIST]
>              preserve the specified attributes (default:
mode,ownership,timestamps), if possible additional attributes: context,
links, xattr, all

Upon reading this I wrongly assumed that _failing to provide a preserve
parameter_, it would preserve by default the mode, ownership and timestamps.

I was annoyed on it seeing I needed to manually add
--preserve=mode,ownership,timestamps and it wasn't working 'as
documented' until I found the explanation in the Texinfo manual:

>Using `--preserve' with no ATTRIBUTE_LIST is equivalent to
>     `--preserve=mode,ownership,timestamps'.
>In the absence of this option, each destination file is created
>     with the mode bits of the corresponding source file, minus the
>     bits set in the umask and minus the set-user-ID and set-group-ID
>     bits.  *Note File permissions::.


I am attaching a rewording proposal that avoids talking about "the
default". If the mailing list strips plain text attachments I can send
it to you directly.


PS: You may want to fix
http://www.gnu.org/software/coreutils/faq/coreutils-faq.html there're
<samp> html tags visible inside anchor tags.

diff --git a/src/cp.c b/src/cp.c
index c99aff3..5577c89 100644
--- a/src/cp.c
+++ b/src/cp.c
@@ -181,10 +181,10 @@ Mandatory arguments to long options are mandatory for 
short options too.\n\
 "), stdout);
       fputs (_("\
   -p                           same as --preserve=mode,ownership,timestamps\n\
-      --preserve[=ATTR_LIST]   preserve the specified attributes (default:\n\
-                                 mode,ownership,timestamps), if possible\n\
-                                 additional attributes: context, links, 
xattr,\n\
-                                 all\n\
+      --preserve[=ATTR_LIST]   preserve the specified attributes (without\n\
+                                 ATTR_LIST: mode,ownership,timestamps), if\n\
+                                 possible. Additional attributes: context,\n\
+                                 links, xattr, all\n\
 "), stdout);
       fputs (_("\
       --no-preserve=ATTR_LIST  don't preserve the specified attributes\n\