makepkg: calculate exact total file size

The current calculation of the total file size for a package using "du"
suffers from issues in portability and correctness.  Especially on btrfs,
this can result in clearly wrong package information such as:

Download Size  : 14684.29 KiB
Installed Size : 7628.00 KiB

Use an approach based on "stat" to calculate total file size.

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

configure.ac

@@ -245,7 +245,6 @@ 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

@@ -53,7 +53,6 @@ edit = sed \
 	-e 's|@BUILDSCRIPT[@]|$(BUILDSCRIPT)|g' \
 	-e 's|@SIZECMD[@]|$(SIZECMD)|g' \
 	-e 's|@SEDINPLACE[@]|$(SEDINPLACE)|g' \
-	-e 's|@DUPATH[@]|$(DUPATH)|g' \
 	-e 's|@SCRIPTNAME[@]|$@|g' \
 	-e 's|@configure_input[@]|Generated from $@.sh.in; do not edit by hand.|g'
 

scripts/makepkg.sh.in

@@ -1109,8 +1109,7 @@ write_pkginfo() {
 	else
 		local packager="Unknown Packager"
 	fi
-	local size="$(@DUPATH@ -sk)"
-	size="$(( ${size%%[^0-9]*} * 1024 ))"
+	local size="$(find . -print0 | xargs -0 @SIZECMD@ | awk '{ sum += $1 } END { print sum }')"
 
 	msg2 "$(gettext "Generating %s file...")" ".PKGINFO"
 	echo "# Generated by makepkg $myver"