apr: Fix ptests on musl

musl does not implement dlclose [1] the way apr tests it will always
fail, even though it is per posix. Backport a relevant fix

[1] https://wiki.musl-libc.org/functional-differences-from-glibc.html#Unloading-libraries

(From OE-Core rev: cc694b2dcaa8df255f39feff0b99b8b10090bc4f)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/apr/apr/0001-dso-Check-for-NULL-handle-in-apr_dso_sym.patch

@@ -0,0 +1,37 @@
+From a25be1aaa92a6d2e7f4cc3fdfbb92e5a10b63035 Mon Sep 17 00:00:00 2001
+From: Greg Beard <gmbeard@googlemail.com>
+Date: Sat, 25 Mar 2023 08:31:36 +0000
+Subject: [PATCH] dso: Check for NULL handle in apr_dso_sym
+
+Upstream-Status: Backport [https://github.com/apache/apr/pull/40/commits/0efce00093b1ba405d91c7f0eab9755c8527eead]
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ dso/unix/dso.c | 12 ++++++++++++
+ 1 file changed, 12 insertions(+)
+
+diff --git a/dso/unix/dso.c b/dso/unix/dso.c
+index fdd56f1..583d5de 100644
+--- a/dso/unix/dso.c
++++ b/dso/unix/dso.c
+@@ -173,6 +173,18 @@ APR_DECLARE(apr_status_t) apr_dso_sym(apr_dso_handle_sym_t *ressym,
+                                       apr_dso_handle_t *handle, 
+                                       const char *symname)
+ {
++    /* This is necessary for `testdso.c`. For some reason, musl
++     * builds fail the `test_unload_library` test if the below
++     * check isn't in place. `test_unload_library` unloads the
++     * library and then immediately calls this function. Maybe
++     * musl's `dlsym()` assumes the handle is never NULL and
++     * some UB is being invoked here...
++     */
++    if (handle->handle == NULL) {
++        handle->errormsg = "library not loaded";
++        return APR_ESYMNOTFOUND;
++    }
++
+ #if defined(DSO_USE_SHL)
+     void *symaddr = NULL;
+     int status;
+-- 
+2.42.0
+

meta/recipes-support/apr/apr_1.7.4.bb

@@ -23,6 +23,7 @@ SRC_URI = "${APACHE_MIRROR}/apr/${BPN}-${PV}.tar.bz2 \
            file://0001-Add-option-to-disable-timed-dependant-tests.patch \
            file://0001-configure-Remove-runtime-test-for-mmap-that-can-map-.patch \
            file://autoconf-2.73.patch \
+           file://0001-dso-Check-for-NULL-handle-in-apr_dso_sym.patch \
            "
 
 SRC_URI[sha256sum] = "fc648de983f3a2a6c9e78dea1f180639bd2fad6c06d556d4367a701fe5c35577"