From d68208fa16f6716c53d598d3aa65ed1d4659d06a Mon Sep 17 00:00:00 2001
From: Matt Madia <mattmadia@gmail.com>
Date: Sun, 22 Sep 2013 13:57:53 -0400
Subject: [PATCH] Use double parenthesis for math expressions.

This allows FreeBSD with a pure /bin/sh (not a symlink to /bin/bash) to build
the cross-tools to a dedicated directory, outside of the generated folder.
---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index 48d8df7677..a692695629 100755
--- a/configure
+++ b/configure
@@ -574,7 +574,7 @@ while [ $# -gt 0 ] ; do
 			set_variable crossToolsPrefix_$targetArch "$2"
 			targetArchs="$targetArchs $targetArch"
 			HAIKU_PACKAGING_ARCHS=
-			unknownArchIndex=$[$unknownArchIndex + 1]
+			unknownArchIndex=$(($unknownArchIndex + 1))
 			shift 2
 			;;
 		--distro-compatibility)