--with-mailgroup: fix the locking of mail

This should fix rhbz#2040522.

liblockfile.spec

@@ -1,6 +1,6 @@
 Name:           liblockfile
 Version:        1.17
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        This implements a number of functions found in -lmail on SysV systems
 
 # regarding license please see file COPYRIGHT
@@ -31,17 +31,28 @@ developing applications that use %{name}.
 %prep
 %setup -q -n %{name}-%{VERSION}
 
-# remove -g root from install
-sed -i "s/-g root//" Makefile.in
+# There are occurrences of "install -g GROUP ...".
+#
+# Changing the group requires permissions that are normally not
+# available while packaging.
+#
+# Let's remove "-g GROUP".
+sed -Ei "/install/ s/-g [^ ]+//" Makefile.in
 
+# Makefile.in mixes and messes with DESTDIR and prefix.
+# See the following pull requests submitted upstream:
+# https://github.com/miquels/liblockfile/pull/11
+# https://github.com/miquels/liblockfile/pull/15
+sed -i \
+    -e '/^prefix/s,\$(DESTDIR),,' \
+    -e 's,\(\$(\(lib\|include\|man\|nfslock\|bin\)dir)\),$(DESTDIR)\1,' \
+    -e '/-DLOCKPROG/s,\$(DESTDIR),,' Makefile.in
 
 %build
-%configure --enable-shared --prefix=%{buildroot} --bindir=%{buildroot}%{_bindir} --mandir=%{buildroot}%{_mandir} --libdir=%{buildroot}%{_libdir} --includedir=%{buildroot}%{_includedir}
+%configure --enable-shared --with-mailgroup
 %make_build
 
-
 %install
-export DESTDIR=%{buildroot}
 %make_install
 
 ldconfig -N -n %{buildroot}/%{_libdir}
@@ -66,6 +77,9 @@ ldconfig -N -n %{buildroot}/%{_libdir}
 
 
 %changelog
+* Tue May 17 2022 Fabrice Bauzac-Stehly <noon@mykolab.com> - 1.17-2
+- Enable --with-mailgroup (rhbz#2040522)
+
 * Fri Jan 28 2022 Richard Lescak <rlescak@redhat.com> - 1.17-1
 - Rebase to version 1.17