tools/patch: apply patch for EACCES on xattr copy

When compiling OpenWRT on a compressed btrfs volume the build fails in
libtool.
The file `libltdl/config/ltmain.m4sh` from `libtool-2.4.2.tar.xz` is
missing write permissions, therefore patch falls back to copying the
file and patching that. During this patch tries to preserve all file
attribute on the new copy.
However the attribute `btrfs.compression` is privileged and btrfs return
EACCES.
While patch ignores multiple other error codes during the copy of xattr
copy it is not prepared for EACCES and aborts.

EACCES should be ignored the same way as the other errors.

Build log:
```
...
Applying ./patches/000-relocatable.patch using plaintext:
patching file libltdl/config/general.m4sh
patching file libtoolize.in
patching file libtoolize.m4sh
patching file libltdl/m4/libtool.m4

Applying ./patches/100-libdir-fixes.patch using plaintext:
patching file libltdl/config/ltmain.m4sh
File libltdl/config/ltmain.sh is read-only; trying to patch anyway
patching file libltdl/config/ltmain.sh
patch: setting attribute btrfs.compression for btrfs.compression: Permission denied
Patch failed!  Please fix ./patches/100-libdir-fixes.patch!
```

Link: https://lists.gnu.org/archive/html/bug-patch/2022-11/msg00000.html
Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>

1 files changed, 33 insertions, 0 deletions

diff --git a/tools/patch/patches/070-don-t-fail-hard-on-EACCES-when-copying-xattrs.patch b/tools/patch/patches/070-don-t-fail-hard-on-EACCES-when-copying-xattrs.patch
new file mode 100644
index 0000000000..e19a9c0845
--- /dev/null
+++ b/tools/patch/patches/070-don-t-fail-hard-on-EACCES-when-copying-xattrs.patch
@@ -0,0 +1,33 @@
+From f42cbe1a91a3a6f79d1eec594ce7c72aec79179b Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <thomas@t-8ch.de>
+Date: Wed, 9 Nov 2022 05:08:22 +0100
+Subject: [PATCH] don't fail hard on EACCES when copying xattrs
+
+On btrfs the xattr "btrfs.compressed" requires privileges to set,
+otherwise EACCES is returned.
+When patch tries to do copy this attribute it receives the error and
+aborts.
+---
+ src/util.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/src/util.c
++++ b/src/util.c
+@@ -182,7 +182,7 @@ copy_attr_error (struct error_context *c
+   int err = errno;
+   va_list ap;
+ 
+-  if (err != ENOSYS && err != ENOTSUP && err != EPERM)
++  if (err != ENOSYS && err != ENOTSUP && err != EPERM && err != EACCES)
+     {
+       /* use verror module to print error message */
+       va_start (ap, fmt);
+@@ -284,7 +284,7 @@ set_file_attributes (char const *to, enu
+     }
+   if (attr & FA_XATTRS)
+     if (copy_attr (from, to) != 0
+-	&& errno != ENOSYS && errno != ENOTSUP && errno != EPERM)
++	&& errno != ENOSYS && errno != ENOTSUP && errno != EPERM && errno != EACCES)
+       fatal_exit (0);
+   if (attr & FA_MODE)
+     {