Added test for libattr; Renamed macros

Signed-off-by: Alexander Hajnal <trinitydesktop@alephnull.net>

CMakeLists.txt

@@ -284,6 +284,15 @@ if( NOT HAVE_SYS_UCRED_H )
   endif( )
 endif( )
 check_include_file( "sys/xattr.h" HAVE_SYS_XATTR_H )
+check_include_file( "attr/libattr.h" HAVE_ATTR_LIBATTR_H)
+if ( HAVE_ATTR_LIBATTR_H )
+    check_library_exists( attr attr_copy_file "" HAVE_ATTR__ATTR_COPY_FILE )
+endif( )
+if( HAVE_ATTR__ATTR_COPY_FILE )
+    set( DO_USER_XATTR_COPYING "1" )
+    message( STATUS "User extended attribute copy support enabled" )
+endif( )
+
 check_include_file( "termios.h" HAVE_TERMIOS_H )
 check_include_file( "termio.h" HAVE_TERMIO_H )
 check_include_file( "unistd.h" HAVE_UNISTD_H )

tdeio/tdeio/README.xattr

@@ -12,11 +12,12 @@ code[4] provided with libattr (examples/copyattr.c).
 This code has been in daily use by the author of this patch for just over five 
 years without any issues.  What's missing though is the addition of tests for 
 xattr and libattr support at configuration/compile time.  The code I've added 
-is enclosed by '#ifdef USE_XATTR' statements so a test should be added that 
-sets this macro[5] if configure-time tests show that xattrs/libattr are working.  
-I don't know how to go about adding such tests though so I've simply included a 
-'#define USE_XATTR 1' statement to the top of the code.  This should obviously 
-be fixed before general release.
+is enclosed by '#ifdef DO_USER_XATTR_COPYING' statements so a test should be 
+added that sets this macro[5] if configure-time tests show that xattrs/libattr 
+are working.  I've added a preliminary test to CMakeLists.txt but I'm not sure 
+it's correct.  Alternatively uncomment the '#define DO_USER_XATTR_COPYING 1' 
+statement at the top of the code to force my code to be enabled.  Ensuring that 
+the cmake test working correctly needs to be done before general release.
 
 This code has been tested on select Ubuntu Linux releases (natty, precise, 
 xenial, and jammy) using x86_64 Linux kernels 3.14.1, 4.18.3, and 5.15.0.
@@ -70,8 +71,9 @@ Enjoy!
 
 [4] The code that this patch is based on is licensed GPL v2 (or later).
 
-[5] One has to use '#define USE_XATTR 1'; specifying '#define USE_XATTR' 
-    doesn't enable the code (at least on my system).
+[5] One has to use '#define DO_USER_XATTR_COPYING 1'; specifying instead  
+   '#define DO_USER_XATTR_COPYING' doesn't enable the code (at least on my 
+   system).
 
 [6] I'm not sure which non-Linux platforms (if any) libattr runs on.
 

tdeio/tdeio/job.cpp

@@ -82,15 +82,20 @@ extern "C" {
 
 
 
-// Set this macro if libattr is installed and working
-#define USE_XATTR 1
+// This macro is set if user extended attribute support is available.
+// Uncomment it here for testing purposes
+//#define DO_USER_XATTR_COPYING 1
+
+// To determine which backend is available check for the following macros:
+// HAVE_ATTR__ATTR_COPY_FILE  ->  attr_copy_file via libattr (Linux)
 
 // Extended attribute support (added AKH 2017-11-26, updated AKH 2022-12-16)
 // Based on copyattr.c by Andreas Gruenbacher (included with libattr)
 // This does NOT also copy Access Control Lists!
 
-#ifdef USE_XATTR
+#ifdef DO_USER_XATTR_COPYING
 
+//#include <stdio.h>  // For stderr, (v)fprintf (already included above)
 //#include <errno.h>  // For errno (already included above)
 //#include <stdlib.h> // For free (already included above)
 //#include <string.h> // For errno, strdup, and strcmp (already implictly included above)
@@ -2043,7 +2048,7 @@ void FileCopyJob::slotResult( TDEIO::Job *job)
    {
       m_copyJob = 0;
 
-#ifdef USE_XATTR
+#ifdef DO_USER_XATTR_COPYING
       {
           // Copy extended attributes (added AKH 2017-11-26)
           attr_copy_file(TQFile::encodeName(m_src.path()), TQFile::encodeName(m_dest.path()), NULL, &ctx);