cp: -a now preserves SELinux context, with reduced diagnostics

* copy.c (copy_reg): Reduce SELinux context diagnostics for 'cp -a'.
(copy_internal): Likewise
* copy.h (cp_options): Add boolean reduce_diagnostics.
* cp.c (usage): Say that --archive (-a) behaves like -dR --preserve=all.
(cp_option_init): Initialize added reduce_diagnostics.
(main): Add reduce_diagnostics for the -a option, and preserve SELinux
context, if possible.
* mv.c (cp_options_init): Initialize new cp_options booleans.
* install.c (cp_option_init): Likewise.
* NEWS: Mention those behaviour changes.
* doc/coreutils.texi: Document --preserve=context, document that
diagnostics are not shown for failures of non-mandatory attributes
(just SELinux at the moment).
* tests/cp/cp-a-selinux: Check not only failures, but succesful use
of preserving SELinux context in cp.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/cp.c b/src/cp.c
index 9171fa652..57907cc79 100644
--- a/src/cp.c
+++ b/src/cp.c
@@ -160,7 +160,7 @@ Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.\n\
 Mandatory arguments to long options are mandatory for short options too.\n\
 "), stdout);
       fputs (_("\
-  -a, --archive                same as -dpR\n\
+  -a, --archive                same as -dR --preserve=all\n\
       --backup[=CONTROL]       make a backup of each existing destination file\n\
   -b                           like --backup but does not accept an argument\n\
       --copy-contents          copy contents of special files when recursive\n\
@@ -766,6 +766,7 @@ cp_option_init (struct cp_options *x)
   x->preserve_security_context = false;
   x->require_preserve_context = false;
   x->preserve_xattr = false;
+  x->reduce_diagnostics = false;
   x->require_preserve_xattr = false;
 
   x->require_preserve = false;
@@ -921,13 +922,16 @@ main (int argc, char **argv)
 				     sparse_type_string, sparse_type);
 	  break;
 
-	case 'a':		/* Like -dpR. */
+	case 'a':		/* Like -dR --preserve=all with reduced failure diagnostics. */
 	  x.dereference = DEREF_NEVER;
 	  x.preserve_links = true;
 	  x.preserve_ownership = true;
 	  x.preserve_mode = true;
 	  x.preserve_timestamps = true;
 	  x.require_preserve = true;
+	  if (selinux_enabled)
+	     x.preserve_security_context = true;
+	  x.reduce_diagnostics = true;
 	  x.recursive = true;
 	  break;