From 42b6dd4293e07ef53dccc006e576e8b9f40614e6 Mon Sep 17 00:00:00 2001
From: Ray Donnelly <mingw.android@gmail.com>
Date: Sat, 12 Apr 2014 15:57:20 +0100
Subject: [PATCH 1/6] functions: Add CT_FindRelativePath

.. needed for Windows due to it lacking a single
hierarchy filesystem.
---
 scripts/functions | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/scripts/functions b/scripts/functions
index a309f2d..60a6793 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -1396,3 +1396,84 @@ CT_DoLoadState(){
     exec >>"${tmp_log_file}"
     rm -f "${state_dir}/tail.log"
 }
+
+# Based on https://github.com/Offirmo/offirmo-shell-lib/blob/master/bin/osl_lib_file.sh
+# .. modified to work with Dash.
+
+# both $1 and $2 are absolute paths beginning with /
+# returns relative path to $2/$target from $1/$source
+CT_FindRelativePath()
+{
+    local insource=$1
+    local intarget=$2
+
+    # Ensure both source and target end with /
+    # This simplifies the inner loop.
+    #echo "insource : \"$insource\""
+    #echo "intarget : \"$intarget\""
+    case "$insource" in
+        */) ;;
+        *) source="$insource"/ ;;
+    esac
+
+    case "$intarget" in
+        */) ;;
+        *) target="$intarget"/ ;;
+    esac
+
+    #echo "source : \"$source\""
+    #echo "target : \"$target\""
+
+    local common_part=$source # for now
+
+    local result=""
+
+    #echo "common_part is now : \"$common_part\""
+    #echo "result is now      : \"$result\""
+    #echo "target#common_part : \"${target#$common_part}\""
+    while [ "${target#$common_part}" = "${target}" -a "${common_part}" != "//" ]; do
+        # no match, means that candidate common part is not correct
+        # go up one level (reduce common part)
+        common_part="$(dirname $common_part)"/
+        # and record that we went back
+        if [ -z "${result}" ]; then
+            result="../"
+        else
+            result="../$result"
+        fi
+        #echo "(w) common_part is now : \"$common_part\""
+        #echo "(w) result is now      : \"$result\""
+        #echo "(w) target#common_part : \"${target#$common_part}\""
+    done
+
+    #echo "(f) common_part is     : \"$common_part\""
+
+    if [ "${common_part}" = "//" ]; then
+        # special case for root (no common path)
+        common_part="/"
+    fi
+
+    # since we now have identified the common part,
+    # compute the non-common part
+    forward_part="${target#$common_part}"
+    #echo "forward_part = \"$forward_part\""
+
+    if [ -n "${result}" -a -n "${forward_part}" ]; then
+        #echo "(simple concat)"
+        result="$result$forward_part"
+    elif [ -n "${forward_part}" ]; then
+        result="$forward_part"
+    fi
+    #echo "result = \"$result\""
+
+    # if a / was added to target and result ends in / then remove it now.
+    if [ "$intarget" != "$target" ]; then
+        case "$result" in
+            */) result=$(echo "$result" | awk '{ string=substr($0, 1, length($0)-1); print string; }' ) ;;
+        esac
+    fi
+
+    echo $result
+
+    return 0
+}
-- 
2.2.1