Workaround for Qemu aarch64 abuild-tar bug (#907)

See also: <https://github.com/postmarketOS/pmbootstrap/issues/546>

main/abuild-aarch64-qemu-workaround/APKBUILD

@@ -0,0 +1,25 @@
+pkgname=abuild-aarch64-qemu-workaround
+pkgver=3.1.0
+pkgrel=0
+pkgdesc="Patched abuild-tar that works with Qemu"
+url="https://github.com/postmarketOS/pmbootstrap/issues/546"
+arch="aarch64"
+license="GPL2"
+depends=""
+install="$pkgname.post-install"
+options="!check"
+source="abuild-$pkgver.tar.gz::https://github.com/alpinelinux/abuild/archive/v$pkgver.tar.gz write-check-count.patch"
+makedepends="libressl-dev"
+
+builddir="$srcdir/abuild-$pkgver"
+build() {
+	make VERSION="$pkgver-r$pkgrel" abuild-tar
+}
+
+package() {
+	cd "$builddir"
+	install -Dm755 abuild-tar "$pkgdir"/usr/bin/abuild-tar-patched
+}
+
+sha512sums="fcdbef96b06a908148d6df41981fca19fe1767274b283efbb3f1adaefc074a4daa7b8eea8d49c533858c464e45b3954f97cd3d0185f0ed7e464244f9802001f5  abuild-3.1.0.tar.gz
+a80c55fe6cb6cc410ca409558c1e1ab8edec9a675031c404cec84c19b4b8460fbbba92db5c1401c0027f8fc0f5be4b82177ec2fad9d734cbc50ca24bfe6e149f  write-check-count.patch"

main/abuild-aarch64-qemu-workaround/abuild-aarch64-qemu-workaround.post-install

@@ -0,0 +1,2 @@
+#!/bin/sh
+ln -svf /usr/bin/abuild-tar-patched /usr/local/bin/abuild-tar

main/abuild-aarch64-qemu-workaround/write-check-count.patch

@@ -0,0 +1,13 @@
+--- a/abuild-tar.c
++++ b/abuild-tar.c
+@@ -156,7 +156,9 @@ static ssize_t full_write(int fd, const void *buf, size_t count)
+ 		count -= n;
+ 	} while (1);
+ 
+-	if (total == 0 && n < 0)
++	// Workaround for Qemu bug: also check for count:
++	// <https://github.com/postmarketOS/pmbootstrap/issues/546>
++	if (total == 0 && n < 0 && count)
+ 		return -errno;
+ 
+ 	return total;