sharutils: Let POSIX_SHELL be overridable from environment

This helps fix
WARNING: sharutils-4.15.2-r0 do_package_qa: QA Issue: File /usr/bin/shar in package sharutils contains reference to TMPDIR

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Armin Kuster <akuster@mvista.com>

meta-oe/recipes-support/sharutils/sharutils/0001-libopts.m4-accept-POSIX_SHELL-from-the-environment-d.patch

@@ -0,0 +1,47 @@
+From fb8bf1c1b1d0bf8e9bc637c0e67219fab1a9eb03 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Wed, 14 Aug 2024 15:24:57 -0700
+Subject: [PATCH] libopts.m4: accept POSIX_SHELL from the environment during
+ the configure step
+
+This lets us set it to the canonical path /bin/bash, even on systems
+where both /bin/bash and /usr/bin/bash are available, and therefore
+which(1) might return /usr/bin/bash (depending on PATH order).
+
+Both copies of libopts.m4 are marked as generated files, but the files
+from which they were generated do not seem to be present in the sharutils
+package. This change is equivalent to part of a 2016 autogen commit
+<https://git.savannah.gnu.org/cgit/autogen.git/commit/?id=db064b9a>.
+
+Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/autogen.git/commit/?id=db064b9a]
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ libopts/m4/libopts.m4 | 1 +
+ m4/libopts.m4         | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/libopts/m4/libopts.m4 b/libopts/m4/libopts.m4
+index 1a896d9..3b88426 100644
+--- a/libopts/m4/libopts.m4
++++ b/libopts/m4/libopts.m4
+@@ -114,6 +114,7 @@ AC_DEFUN([INVOKE_LIBOPTS_MACROS_FIRST],[
+   AC_PROG_SED
+   [while :
+   do
++      test -x "$POSIX_SHELL" && break
+       POSIX_SHELL=`which bash`
+       test -x "$POSIX_SHELL" && break
+       POSIX_SHELL=`which dash`
+diff --git a/m4/libopts.m4 b/m4/libopts.m4
+index c7ba4f3..a1127e1 100644
+--- a/m4/libopts.m4
++++ b/m4/libopts.m4
+@@ -114,6 +114,7 @@ AC_DEFUN([INVOKE_LIBOPTS_MACROS_FIRST],[
+   AC_PROG_SED
+   [while :
+   do
++      test -x "$POSIX_SHELL" && break
+       POSIX_SHELL=`which bash`
+       test -x "$POSIX_SHELL" && break
+       POSIX_SHELL=`which dash`

meta-oe/recipes-support/sharutils/sharutils_4.15.2.bb

@@ -13,10 +13,13 @@ SRC_URI = "${GNU_MIRROR}/${BPN}/${BP}.tar.gz \
            file://0001-Fix-building-with-GCC-10.patch \
            file://0002-Do-not-include-lib-md5.c-into-src-shar.c.patch \
            file://0001-configure.ac-Check-and-define-intmax_t-type.patch \
+           file://0001-libopts.m4-accept-POSIX_SHELL-from-the-environment-d.patch \
            "
 SRC_URI[md5sum] = "32a51b23e25ad5e6af4b89f228be1800"
 SRC_URI[sha256sum] = "ee336e68549664e7a19b117adf02edfdeac6307f22e5ba78baca457116914637"
 
+EXTRA_OECONF = "POSIX_SHELL=${base_bindir}/sh"
+
 do_install:append() {
     if [ -e ${D}${libdir}/charset.alias ]
     then