Fix multilib conflicts in lvconfig.h

The multilib header handling is copied verbatim from libjpeg-turbo.

libvisual.spec

@@ -2,7 +2,7 @@
 
 Name:           libvisual
 Version:        0.4.0
-Release:        29%{?dist}
+Release:        30%{?dist}
 Epoch:		1
 Summary:        Abstraction library for audio visualisation plugins
 License:        LGPLv2+
@@ -54,6 +54,44 @@ make %{?_smp_mflags}
 
 %install
 make install DESTDIR=%{buildroot}
+
+# Avoid multilib conflicts
+case `uname -i` in
+  i386 | ppc | s390 | sparc )
+    wordsize="32"
+    ;;
+  x86_64 | ppc64 | s390x | sparc64 )
+    wordsize="64"
+    ;;
+  *)
+    wordsize=""
+    ;;
+esac
+
+if test -n "$wordsize"
+then
+  mv %{buildroot}%{_includedir}/libvisual-%{smallversion}/libvisual/lvconfig.h \
+     %{buildroot}%{_includedir}/libvisual-%{smallversion}/libvisual/lvconfig-$wordsize.h
+
+  cat >%{buildroot}%{_includedir}/libvisual-%{smallversion}/libvisual/lvconfig.h <<EOF
+#ifndef __LV_CONFIG_H_MULTILIB__
+#define __LV_CONFIG_H_MULTILIB__
+
+#include <bits/wordsize.h>
+
+#if __WORDSIZE == 32
+# include "lvconfig-32.h"
+#elif __WORDSIZE == 64
+# include "lvconfig-64.h"
+#else
+# error "unexpected value for __WORDSIZE macro"
+#endif
+
+#endif
+EOF
+
+fi
+
 find %{buildroot} -type f -name "*.la" -exec rm -f {} ';'
 
 %find_lang %{name}-%{smallversion}
@@ -73,6 +111,9 @@ find %{buildroot} -type f -name "*.la" -exec rm -f {} ';'
 
 
 %changelog
+* Fri Jan 15 2021 Kalev Lember <klember@redhat.com> - 1:0.4.0-30
+- Fix multilib conflicts in lvconfig.h
+
 * Tue Jul 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 1:0.4.0-29
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild