mv: emit warnings when copying extended attributes fails with ENOTSUP

* src/copy.c (copy_reg, copy_interal): Don't change the exit status if
copying extended attributes fails and we are 'mv'.
* src/copy.h (struct cp_options): Update some commentary.
* src/mv.c (cp_option_init): Enable require_preserve_xattr in the
cp_options struct.
* tests/cp/cp-mv-enotsup-xattr.sh: Check that the error is emitted when
'mv' is built with extended attribute support.
* doc/coreutils.texi (mv invocation): Mention that all errors are
emitted, but do not modify the exit status.
* NEWS: Mention the bug fix.
Fixes https://bugs.gnu.org/13601

NEWS

@@ -26,6 +26,10 @@ GNU coreutils NEWS                                    -*- outline -*-
   'head' and 'tail' now quote names in file headers when needed.
   [This bug was present in "the beginning".]
 
+  'mv' now warns when copying extended attributes fails with ENOTSUP, e.g., when
+  moving files to a file system that does not support them.
+  [bug introduced in coreutils-7.3]
+
   'numfmt', 'printf', and 'seq' on Solaris, no longer output an extraneous e+00
   when using a large precision like "%.5119f".
   [This bug was present in "the beginning".]

doc/coreutils.texi

@@ -9981,7 +9981,8 @@ original file system.
 @cindex extended attributes, xattr
 @command{mv} always tries to copy extended attributes (xattr), which may
 include SELinux context, ACLs or Capabilities.
-Upon failure all but @samp{Operation not supported} warnings are output.
+Upon failure all warnings are emitted, but do not modify the exit
+status.
 
 @cindex prompting, and @command{mv}
 If a destination file exists but is normally unwritable, standard input

src/copy.c

@@ -1086,7 +1086,7 @@ copy_reg (char const *src_name, char const *dst_name,
   if (preserve_xattr)
     {
       if (!copy_attr (src_name, source_desc, dst_name, dest_desc, x)
-          && x->require_preserve_xattr)
+          && x->require_preserve_xattr && ! x->move_mode)
         return_val = false;
     }
 
@@ -2672,7 +2672,7 @@ skip:
 
   /* Set xattrs after ownership as changing owners will clear capabilities.  */
   if (x->preserve_xattr && ! copy_attr (src_name, -1, dst_name, -1, x)
-      && x->require_preserve_xattr)
+      && x->require_preserve_xattr && ! x->move_mode)
     return false;
 
   /* The operations beyond this point may dereference a symlink.  */

src/copy.h

@@ -234,12 +234,11 @@ struct cp_options
      while with 'cp --preserve=all' or 'cp -a', it is "false". */
   bool require_preserve_xattr;
 
-  /* This allows us to output warnings in cases 2 and 4 below,
+  /* This allows us to output warnings in case 2 below,
      while being quiet for case 1 (when reduce_diagnostics is true).
        1. cp -a                       try to copy xattrs with no errors
        2. cp --preserve=all           copy xattrs with all but ENOTSUP warnings
        3. cp --preserve=xattr,context copy xattrs with all errors
-       4. mv                          copy xattrs with all but ENOTSUP warnings
    */
   bool reduce_diagnostics;
 

src/mv.c

@@ -145,7 +145,7 @@ cp_option_init (struct cp_options *x)
   x->require_preserve = false;  /* FIXME: maybe make this an option */
   x->require_preserve_context = false;
   x->preserve_xattr = true;
-  x->require_preserve_xattr = false;
+  x->require_preserve_xattr = true;
   x->recursive = true;
   x->sparse_mode = SPARSE_AUTO;  /* FIXME: maybe make this an option */
   x->symbolic_link = false;

tests/cp/cp-mv-enotsup-xattr.sh

@@ -110,10 +110,18 @@ compare exp err     || fail=1
 
 rm -f err noxattr/a
 
-# This should pass without diagnostics
+# POSIX requires a diagnostic to be printed here without
+# modifying the exit status.
 mv xattr/a noxattr/ 2>err || fail=1
 test -s noxattr/a         || fail=1  # destination file must not be empty
-compare /dev/null err || fail=1
+if grep '^#define USE_XATTR 1' $CONFIG_HEADER > /dev/null; then
+cat <<EOF > exp || framework_failure_
+mv: setting attributes for 'noxattr/a': $ENOTSUP
+EOF
+else
+truncate -s0 exp || framework_failure_
+fi
+compare exp err || fail=1
 
 # This should pass and copy xattrs of the symlink
 # since the xattrs used here are not in the 'user.' namespace.