#!/bin/sh

# PRE-REVPROP-CHANGE HOOK
#
# The pre-revprop-change hook is invoked before a revision property
# is modified.  Subversion runs this hook by invoking a program
# (script, executable, binary, etc.) named 'pre-revprop-change' (for which
# this file is a template), with the following ordered arguments:
#
#   [1] REPOS-PATH   (the path to this repository)
#   [2] REVISION     (the revision being tweaked)
#   [3] USER         (the username of the person tweaking the property)
#   [4] PROPNAME     (the property being set on the revision)
#
#   [STDIN] PROPVAL  ** the property value is passed via STDIN.
#
# If the hook program exits with success, the propchange happens; but
# if it exits with failure (non-zero), the propchange doesn't happen.
# The hook program can use the 'svnlook' utility to examine the 
# existing value of the revision property.
#
# WARNING: unlike other hooks, this hook MUST exist for revision
# properties to be changed.  If the hook does not exist, Subversion 
# will behave as if the hook were present, but failed.  The reason
# for this is that revision properties are UNVERSIONED, meaning that
# a successful propchange is destructive;  the old value is gone
# forever.  We recommend the hook back up the old value somewhere.
#
# On a Unix system, the normal procedure is to have 'pre-revprop-change'
# invoke other programs to do the real work, though it may do the
# work itself too.
#
# Note that 'pre-revprop-change' must be executable by the user(s) who will
# invoke it (typically the user httpd runs as), and that user must
# have filesystem-level permission to access the repository.
#
# On a Windows system, you should name the hook program
# 'pre-revprop-change.bat' or 'pre-revprop-change.exe',
# but the basic idea is the same.
#
# Here is an example hook script, for a Unix /bin/sh interpreter:

REPOS="$1"
REV="$2"
USER="$3"
PROPNAME="$4"

if [ "$PROPNAME" = "svn:log" ]; then exit 0; fi
exit 1