From c71898649e300d7e5700cd247d7ae994c7faa406 Mon Sep 17 00:00:00 2001
From: Koen Kooi <koen@dominion.thruhere.net>
Date: Tue, 16 Aug 2011 16:04:35 +0200
Subject: [PATCH] Upstream: not yet

Fix configure to accept "--prefix=" (a blank prefix).

Upstream-Status: Pending
---
 build/make/configure.sh | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/build/make/configure.sh b/build/make/configure.sh
index 8220d5cbe..923daf8bc 100644
--- a/build/make/configure.sh
+++ b/build/make/configure.sh
@@ -699,6 +699,8 @@ process_common_cmdline() {
         ;;
       --prefix=*)
         prefix="${optval}"
+        # Distinguish between "prefix not set" and "prefix set to ''"
+        prefixset=1
         ;;
       --libdir=*)
         libdir="${optval}"
@@ -728,13 +730,23 @@ process_cmdline() {
 }
 
 post_process_common_cmdline() {
-  prefix="${prefix:-/usr/local}"
+  if [ "$prefixset" != "1" ]
+  then
+      prefix=/usr/local
+  fi
+
+  # Strip trailing slash
   prefix="${prefix%/}"
+
   libdir="${libdir:-${prefix}/lib}"
   libdir="${libdir%/}"
-  if [ "${libdir#${prefix}}" = "${libdir}" ]; then
-    die "Libdir ${libdir} must be a subdirectory of ${prefix}"
-  fi
+
+  case "$libdir" in
+      "${prefix}/"*) ;;
+      *)
+          die "Libdir ${libdir} must be a subdirectory of ${prefix}"
+          ;;
+  esac
 }
 
 post_process_cmdline() {