postfix: fix build with glibc 2.34

Backport a patch to fix build against glibc 2.34 (e.g. on Fedora 35)

Fixes:
| In file included from attr_clnt.c:88:
| /usr/include/unistd.h:363:13: error: conflicting types for
‘closefrom’; have ‘void(int)’
|   363 | extern void closefrom (int __lowfd) __THROW;
|       |             ^~~~~~~~~
| In file included from attr_clnt.c:87:
| ./sys_defs.h:1506:12: note: previous declaration of ‘closefrom’ with
type ‘int(int)’
|  1506 | extern int closefrom(int);
|       |            ^~~~~~~~~

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>

meta-networking/recipes-daemons/postfix/files/0001-fix-build-with-glibc-2.34.patch

@@ -0,0 +1,46 @@
+From 1f25dae3f38548bad32c5a3ebee4c07938d8c1b8 Mon Sep 17 00:00:00 2001
+From: Yi Zhao <yi.zhao@windriver.com>
+Date: Thu, 30 Dec 2021 10:35:57 +0800
+Subject: [PATCH] fix build with glibc 2.34
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The closefrom() function which is introduced in glibc 2.34 conflicts
+with the one provided by postfix.
+
+Fixes:
+| In file included from attr_clnt.c:88:
+| /usr/include/unistd.h:363:13: error: conflicting types for ‘closefrom’; have ‘void(int)’
+|   363 | extern void closefrom (int __lowfd) __THROW;
+|       |             ^~~~~~~~~
+| In file included from attr_clnt.c:87:
+| ./sys_defs.h:1506:12: note: previous declaration of ‘closefrom’ with type ‘int(int)’
+|  1506 | extern int closefrom(int);
+|       |            ^~~~~~~~~
+
+Upstream-Status: Backport
+[https://github.com/vdukhovni/postfix/commit/3d966d3bd5f95b2c918aefb864549fa9f0442e24]
+
+Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
+---
+ src/util/sys_defs.h | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/src/util/sys_defs.h b/src/util/sys_defs.h
+index 39daa16..5de5855 100644
+--- a/src/util/sys_defs.h
++++ b/src/util/sys_defs.h
+@@ -827,6 +827,9 @@ extern int initgroups(const char *, int);
+ #define HAVE_POSIX_GETPW_R
+ #endif
+ #endif
++#if HAVE_GLIBC_API_VERSION_SUPPORT(2, 34)
++#define HAS_CLOSEFROM
++#endif
+ 
+ #endif
+ 
+-- 
+2.17.1
+

meta-networking/recipes-daemons/postfix/postfix_3.4.12.bb

@@ -13,6 +13,7 @@ SRC_URI += "ftp://ftp.porcupine.org/mirrors/postfix-release/official/postfix-${P
            file://postfix-install.patch \
            file://icu-config.patch \
            file://0001-makedefs-add-lnsl-and-lresolv-to-SYSLIBS-by-default.patch \
+           file://0001-fix-build-with-glibc-2.34.patch \
            "
 SRC_URI[sha256sum] = "18555183ae8b52a9e76067799279c86f9f2770cdef3836deb8462ee0a0855dec"
 UPSTREAM_CHECK_REGEX = "postfix\-(?P<pver>3\.3(\.\d+)+).tar.gz"