busybox: avoid use of xopen_as_uid_gid() in `crontab` applet

Issue https://github.com/termux/termux-packages/issues/4837.

packages/busybox/0008-miscutils-crontab.patch

@@ -1,11 +1,13 @@
 diff -uNr busybox-1.31.1/miscutils/crontab.c busybox-1.31.1.mod/miscutils/crontab.c
 --- busybox-1.31.1/miscutils/crontab.c	2019-06-10 13:50:53.000000000 +0300
-+++ busybox-1.31.1.mod/miscutils/crontab.c	2020-01-29 23:25:22.817488323 +0200
-@@ -53,10 +53,12 @@
++++ busybox-1.31.1.mod/miscutils/crontab.c	2020-01-30 14:58:07.338588354 +0200
+@@ -51,12 +51,14 @@
+ 		return;
+ 	}
  
++#ifndef __ANDROID__
  	/* CHILD - change user and run editor */
  	/* initgroups, setgid, setuid */
-+#ifndef __ANDROID__
  	change_identity(pas);
  	setup_environment(pas->pw_shell,
  			SETUP_ENV_CHANGEENV | SETUP_ENV_TO_TMP,
@@ -14,15 +16,29 @@ diff -uNr busybox-1.31.1/miscutils/crontab.c busybox-1.31.1.mod/miscutils/cronta
  	ptr = getenv("VISUAL");
  	if (!ptr) {
  		ptr = getenv("EDITOR");
-@@ -158,7 +160,6 @@
+@@ -129,7 +131,11 @@
+ 		if (!argv[0])
+ 			bb_show_usage();
+ 		if (NOT_LONE_DASH(argv[0])) {
++#ifndef __ANDROID__
+ 			src_fd = xopen_as_uid_gid(argv[0], O_RDONLY, pas->pw_uid, pas->pw_gid);
++#else
++			src_fd = xopen3(argv[0], O_RDONLY, 0600);
++#endif
+ 		}
+ 	}
+ 
+@@ -158,7 +164,9 @@
  		/* No O_EXCL: we don't want to be stuck if earlier crontabs
  		 * were killed, leaving stale temp file behind */
  		src_fd = xopen3(tmp_fname, O_RDWR|O_CREAT|O_TRUNC, 0600);
--		fchown(src_fd, pas->pw_uid, pas->pw_gid);
++#ifndef __ANDROID__
+ 		fchown(src_fd, pas->pw_uid, pas->pw_gid);
++#endif
  		fd = open(pas->pw_name, O_RDONLY);
  		if (fd >= 0) {
  			bb_copyfd_eof(fd, src_fd);
-@@ -167,7 +168,8 @@
+@@ -167,7 +175,8 @@
  		}
  		close_on_exec_on(src_fd); /* don't want editor to see this fd */
  		edit_file(pas, tmp_fname);

packages/busybox/build.sh

@@ -2,7 +2,7 @@ TERMUX_PKG_HOMEPAGE=https://busybox.net/
 TERMUX_PKG_DESCRIPTION="Tiny versions of many common UNIX utilities into a single small executable"
 TERMUX_PKG_LICENSE="GPL-2.0"
 TERMUX_PKG_VERSION=1.31.1
-TERMUX_PKG_REVISION=5
+TERMUX_PKG_REVISION=6
 TERMUX_PKG_SRCURL=https://busybox.net/downloads/busybox-${TERMUX_PKG_VERSION}.tar.bz2
 TERMUX_PKG_SHA256=d0f940a72f648943c1f2211e0e3117387c31d765137d92bd8284a3fb9752a998
 TERMUX_PKG_BUILD_IN_SRC=true