musl: backport reallocarray.

It's in POSIX-future and some applications have started depending on it.
It's easier to backport into musl than fix each individual package.

Since we are adding a new interface to libc, update common/shlibs entry
as well. This should probably have been done for all musl updates.

common/shlibs

@@ -16,7 +16,7 @@
 # PLEASE NOTE: when multiple packages provide the same SONAME, the first
 # one (order top->bottom) is preferred over the next ones.
 #
-libc.so musl-1.1.21_1
+libc.so musl-1.1.24_7
 libc.so.6 glibc-2.32_1
 libm.so.6 glibc-2.32_1
 libpthread.so.0 glibc-2.32_1

srcpkgs/musl/patches/reallocarray.patch

@@ -0,0 +1,42 @@
+From 821083ac7b54eaa040d5a8ddc67c6206a175e0ca Mon Sep 17 00:00:00 2001
+From: Ariadne Conill <ariadne@dereferenced.org>
+Date: Sat, 1 Aug 2020 08:26:35 -0600
+Subject: [PATCH] implement reallocarray
+
+reallocarray is an extension introduced by OpenBSD, which introduces
+calloc overflow checking to realloc.
+
+glibc 2.28 introduced support for this function behind _GNU_SOURCE,
+while glibc 2.29 allows its usage in _DEFAULT_SOURCE.
+
+diff --git a/include/stdlib.h b/include/stdlib.h
+index 194c2033..b54a051f 100644
+--- include/stdlib.h
++++ include/stdlib.h
+@@ -145,6 +145,7 @@ int getloadavg(double *, int);
+ int clearenv(void);
+ #define WCOREDUMP(s) ((s) & 0x80)
+ #define WIFCONTINUED(s) ((s) == 0xffff)
++void *reallocarray (void *, size_t, size_t);
+ #endif
+
+ #ifdef _GNU_SOURCE
+diff --git a/src/malloc/reallocarray.c b/src/malloc/reallocarray.c
+new file mode 100644
+index 00000000..4a6ebe46
+--- /dev/null
++++ src/malloc/reallocarray.c
+@@ -0,0 +1,13 @@
++#define _BSD_SOURCE
++#include <errno.h>
++#include <stdlib.h>
++
++void *reallocarray(void *ptr, size_t m, size_t n)
++{
++	if (n && m > -1 / n) {
++		errno = ENOMEM;
++		return 0;
++	}
++
++	return realloc(ptr, m * n);
++}

srcpkgs/musl/template

@@ -2,7 +2,7 @@
 pkgname=musl
 reverts="1.2.0_1"
 version=1.1.24
-revision=6
+revision=7
 archs="*-musl"
 bootstrap=yes
 build_style=gnu-configure