From: Johannes 'josch' Schauer <josch@debian.org>
Date: Tue, 4 Dec 2018 20:57:48 +0100
X-Dgit-Generated: 8.30-1.1 2474a66055eceaf668b315d83ae7b0ae7bf9a4d5
Subject: Prefer renameat2 from glibc over syscall if available

This is necessary for fakechroot to be able to overwrite renameat2 which
is used by mv(1) from coreutils. See #909612

This patch is based on a patch by Andreas Henriksson <andreas@fatal.se>
which was accepted in gnulib git:

https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=c50cf67bd7ff70525f3cb4074f0d9cc1f5c6cf9c

---

--- coreutils-8.30.orig/lib/config.hin
+++ coreutils-8.30/lib/config.hin
@@ -2069,6 +2069,9 @@
 /* Define to 1 if you have the `renameat' function. */
 #undef HAVE_RENAMEAT
 
+/* Define to 1 if you have the `renameat2' function. */
+#undef HAVE_RENAMEAT2
+
 /* Define to 1 if you have the `rewinddir' function. */
 #undef HAVE_REWINDDIR
 
--- coreutils-8.30.orig/lib/renameat2.c
+++ coreutils-8.30/lib/renameat2.c
@@ -77,7 +77,10 @@ renameat2 (int fd1, char const *src, int
   int ret_val = -1;
   int err = EINVAL;
 
-#ifdef SYS_renameat2
+#if HAVE_RENAMEAT2
+  ret_val = renameat2 (fd1, src, fd2, dst, flags);
+  err = errno;
+#elif defined SYS_renameat2
   ret_val = syscall (SYS_renameat2, fd1, src, fd2, dst, flags);
   err = errno;
 #elif defined RENAME_EXCL
--- coreutils-8.30.orig/m4/renameat.m4
+++ coreutils-8.30/m4/renameat.m4
@@ -15,7 +15,7 @@ AC_DEFUN([gl_FUNC_RENAMEAT],
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_CHECK_HEADERS([linux/fs.h])
-  AC_CHECK_FUNCS_ONCE([renameat])
+  AC_CHECK_FUNCS_ONCE([renameat renameat2])
   if test $ac_cv_func_renameat = no; then
     HAVE_RENAMEAT=0
   elif test $REPLACE_RENAME = 1; then