build: add mkrevision.sh helper script which properly infers the revision from either svn, git-svn or git work copies

build/mkrevision.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+TOPDIR="${0%mkrevision.sh}"
+
+[ -d "$TOPDIR/../build" ] || {
+	echo "Please execute as ./build/mkrevision.sh" >&2
+	exit 1
+}
+
+(
+	cd "$TOPDIR"
+	if svn info >/dev/null 2>/dev/null; then
+		revision="svn-r$(LC_ALL=C svn info | sed -ne 's/^Revision: //p')"
+	elif git log -1 >/dev/null 2>/dev/null; then
+		revision="svn-r$(LC_ALL=C git log -1 | sed -ne 's/.*git-svn-id: .*@\([0-9]\+\) .*/\1/p')"
+		if [ "$revision" = "svn-r" ]; then
+			revision="git-$(LC_ALL=C git log -1 --pretty=%h)"
+		fi
+	else
+		revision="unknown"
+	fi
+
+	echo "$revision"
+)