makepkg: try standard paths for coreutils du

Attempt to find "du" from coreutils in the standard paths and if
not revert to the version in the users PATH.  Using the full path
prevents issues such as FS#19932, where a different and incompatible
version of du is put earlier in the users path.

Signed-off-by: Allan McRae <allan@archlinux.org>

configure.ac

@@ -210,6 +210,7 @@ esac
 
 AM_CONDITIONAL([CYGWIN], test "x$host_os_cygwin" = "xyes")
 AM_CONDITIONAL([DARWIN], test "x$host_os_darwin" = "xyes")
+AC_PATH_PROGS([DUPATH], [du], [du], [/usr/bin$PATH_SEPARATOR/bin] )
 AC_SUBST(SIZECMD)
 AC_SUBST(SEDINPLACE)
 AC_SUBST(STRIP_BINARIES)

scripts/Makefile.am

@@ -42,6 +42,7 @@ edit = sed \
 	-e 's|@BUILDSCRIPT[@]|$(BUILDSCRIPT)|g' \
 	-e 's|@SIZECMD[@]|$(SIZECMD)|g' \
 	-e 's|@SEDINPLACE[@]|$(SEDINPLACE)|g' \
+	-e 's|@DUPATH[@]|$(DUPATH)|g' \
 	-e 's|@configure_input[@]|Generated from $@.in; do not edit by hand.|g'
 
 ## All the scripts depend on Makefile so that they are rebuilt when the

scripts/makepkg.sh.in

@@ -902,7 +902,7 @@ write_pkginfo() {
 	else
 		local packager="Unknown Packager"
 	fi
-	local size="$(du -sk)"
+	local size="$(@DUPATH@ -sk)"
 	size="$(( ${size%%[^0-9]*} * 1024 ))"
 
 	msg2 "$(gettext "Generating .PKGINFO file...")"