Merge from bittboy/buildroot@db180c0

support/download/bzr

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+
+# We want to catch any unexpected failure, and exit immediately
+set -e
+
+# Download helper for bzr, to be called from the download wrapper script
+#
+# Options:
+#   -q          Be quiet
+#   -o FILE     Generate archive in FILE.
+#   -u URI      Clone from repository at URI.
+#   -c CSET     Use changeset (or revision) CSET.
+#   -n NAME     Use basename NAME.
+#
+# Environment:
+#   BZR      : the bzr command to call
+
+
+verbose=
+while getopts "${BR_BACKEND_DL_GETOPTS}" OPT; do
+    case "${OPT}" in
+    q)  verbose=-q;;
+    o)  output="${OPTARG}";;
+    u)  uri="${OPTARG}";;
+    c)  cset="${OPTARG}";;
+    n)  basename="${OPTARG}";;
+    :)  printf "option '%s' expects a mandatory argument\n" "${OPTARG}"; exit 1;;
+    \?) printf "unknown option '%s'\n" "${OPTARG}" >&2; exit 1;;
+    esac
+done
+
+shift $((OPTIND-1)) # Get rid of our options
+
+# Caller needs to single-quote its arguments to prevent them from
+# being expanded a second time (in case there are spaces in them)
+_bzr() {
+    eval ${BZR} "${@}"
+}
+
+# --per-file-timestamps comes with bzr-2.2 (released August 2010),
+# so only pass it if bzr is recent enough. We compute versions as:
+# major*1000 + minor
+bzr_min_version=2002
+bzr_version=$(($(bzr --version |
+                 sed -r -n 's/^Bazaar \(bzr\) ([[:digit:]]+)\.([[:digit:]]+)\..*$/\1*1000+\2/p')
+             ))
+
+# If the version is recent enough, we can generate reproducible
+# archives; otherwise, we just hope for the best (as it would
+# be downloaded from the BR mirror if what we generate here does
+# not match the hash we have for it).
+if [ ${bzr_version} -ge ${bzr_min_version} ]; then
+    timestamp_opt="--per-file-timestamps"
+fi
+
+_bzr export ${verbose} --root="'${basename}/'" --format=tgz \
+    ${timestamp_opt} - "${@}" "'${uri}'" -r "'${cset}'" \
+    >"${output}"