Handle /usr/bin/coreutils -> /bin/coreutils link on postinst/rm

This fixes the installation when using merged-usr

Signed-off-by: Andre Moreira Magalhaes <andre.magalhaes@collabora.com>

debian/changelog

+rust-coreutils (0.0.12-0+apertis4) apertis; urgency=medium
+
+  * Handle /usr/bin/coreutils -> /bin/coreutils link on postinst/rm to fix
+    the installation when using merged-usr
+
+ -- Andre Moreira Magalhaes <andre.magalhaes@collabora.com>  Fri, 18 Feb 2022 17:39:13 -0300
+
 rust-coreutils (0.0.12-0+apertis3) apertis; urgency=medium
 
   * Build a multicall binary instead of multiple binaries

debian/rust-coreutils.links

@@ -12,7 +12,3 @@ usr/bin/hashsum usr/bin/sha3-384sum
 usr/bin/hashsum usr/bin/sha3-512sum
 usr/bin/hashsum usr/bin/shake128sum
 usr/bin/hashsum usr/bin/shake256sum
-# Some binaries are installed in /bin/, some others in /usr/bin/
-# but the upstream makefile doesn't handle this when it creates symlinks.
-# So, we need to create another symlink to make binaries in /usr/bin/ working
-bin/coreutils   usr/bin/coreutils

debian/rust-coreutils.postinst

+#!/bin/sh
+
+# Some binaries are installed in /bin/, some others in /usr/bin/
+# but the upstream makefile doesn't handle this when it creates symlinks.
+# So, we need to create another symlink to make binaries in /usr/bin/ work
+# when not using merged-usr.
+if [ "$1" = 'configure' -a ! -e '/usr/bin/coreutils' ]; then
+  ln -s /bin/coreutils /usr/bin/coreutils
+fi
+
+#DEBHELPER#

debian/rust-coreutils.postrm

+#!/bin/sh
+
+if [ "$1" = 'remove' -a -L '/usr/bin/coreutils' ]; then
+  rm /usr/bin/coreutils
+fi
+
+#DEBHELPER#