[build] check getxattr before attr_get and -lattr

check getxattr before attr_get and -lattr;
do not link with -lattr if getxattr is available from glibc

(modern glibc systems do not require libattr-devel build dependency)

configure.ac

@@ -489,16 +489,6 @@ AC_MSG_RESULT([$WITH_ATTR])
 
 if test "$WITH_ATTR" != no; then
   have_xattr=no
-  # libattr (linux only?)
-  AC_CHECK_LIB([attr], [attr_get], [
-    AC_CHECK_HEADERS([attr/attributes.h], [
-      ATTR_LIB=-lattr
-      AC_DEFINE([HAVE_XATTR], [1], [libattr])
-      AC_DEFINE([HAVE_ATTR_ATTRIBUTES_H], [1])
-      have_xattr=yes
-    ])
-  ])
-  AC_SUBST([ATTR_LIB])
 
   # Linux getxattr
   AC_CHECK_FUNC([getxattr], [
@@ -518,6 +508,19 @@ if test "$WITH_ATTR" != no; then
     ])
   ])
 
+  # libattr (linux only?)
+  if test "$have_xattr" = no; then
+    AC_CHECK_LIB([attr], [attr_get], [
+      AC_CHECK_HEADERS([attr/attributes.h], [
+        ATTR_LIB=-lattr
+        AC_DEFINE([HAVE_XATTR], [1], [libattr])
+        AC_DEFINE([HAVE_ATTR_ATTRIBUTES_H], [1])
+        have_xattr=yes
+      ])
+    ])
+  fi
+  AC_SUBST([ATTR_LIB])
+
   if test "$have_xattr" = no; then
     AC_MSG_ERROR([no backend found implementing extended attributes])
   fi

src/CMakeLists.txt

@@ -272,9 +272,13 @@ endmacro(XCONFIG _package _include_DIR _link_DIR _link_FLAGS _cflags)
 if(WITH_XATTR)
 	check_include_files("sys/types.h;sys/xattr.h" HAVE_SYS_XATTR_H)
 	check_function_exists(getxattr HAVE_XATTR)
-	check_include_files("sys/types.h;attr/attributes.h" HAVE_ATTR_ATTRIBUTES_H)
-	if(HAVE_ATTR_ATTRIBUTES_H)
-		check_library_exists(attr attr_get "" HAVE_XATTR)
+	check_include_files("sys/types.h;sys/extattr.h" HAVE_SYS_EXTATTR_H)
+	check_function_exists(extattr_get_file HAVE_EXTATTR)
+	if(NOT HAVE_XATTR AND NOT HAVE_EXTATTR)
+		check_include_files("sys/types.h;attr/attributes.h" HAVE_ATTR_ATTRIBUTES_H)
+		if(HAVE_ATTR_ATTRIBUTES_H)
+			check_library_exists(attr attr_get "" HAVE_XATTR)
+		endif()
 	endif()
 else()
 	unset(HAVE_ATTR_ATTRIBUTES_H)

src/config.h.cmake

@@ -39,6 +39,8 @@
 #cmakedefine HAVE_ATTR_ATTRIBUTES_H
 #cmakedefine HAVE_SYS_XATTR_H
 #cmakedefine HAVE_XATTR
+#cmakedefine HAVE_SYS_EXTATTR_H
+#cmakedefine HAVE_EXTATTR
 
 /* mySQL */
 #cmakedefine  HAVE_MYSQL_H

src/meson.build

@@ -656,6 +656,15 @@ if get_option('with_xattr')
     )
 	conf_data.set('HAVE_SYS_XATTR_H', true)
 	conf_data.set('HAVE_XATTR', true)
+    elif compiler.has_function('extattr_get_file',
+		args: defs,
+		prefix: '''
+			#include <sys/types.h>
+			#include <sys/extattr.h>
+		'''
+    )
+	conf_data.set('HAVE_SYS_EXTATTR_H', true)
+	conf_data.set('HAVE_EXTATTR', true)
     else
 	libattr = [ compiler.find_library('attr') ]
 	if not(compiler.has_function('attr_get',