Index: svnadmin/hooks/scripts/log-police.py
===================================================================
--- svnadmin/hooks/scripts/log-police.py	(revision 286375)
+++ svnadmin/hooks/scripts/log-police.py	(revision 286376)
@@ -1,160 +1,166 @@
 #!/usr/local/bin/python
 
 # $FreeBSD$
 # http://svn.collab.net/repos/svn/trunk/tools/hook-scripts/log-police.py
 
 # log-police.py: Ensure that log messages end with a single newline.
 # See usage() function for details, or just run with no arguments.
 
 import os
 import sys
 import getopt
 try:
   my_getopt = getopt.gnu_getopt
 except AttributeError:
   my_getopt = getopt.getopt
 
 import svn
 import svn.fs
 import svn.repos
 import svn.core
 
 
 # Pretend we have true booleans on older python versions
 # How old???
 try:
   True
 except:
   True = 1
   False = 0
 
 
 def fix_log_message(log_message):
   "Return a fixed version of LOG_MESSAGE."
   s = ""
   # Pretend leading blanks are adjacent to another
   lastblank = True
   for line in log_message.splitlines():
     line = line.rstrip()
     # Remove duplicate blank lines
     if line == "":
       if lastblank:
 	continue
       lastblank = True
     else:
       lastblank = False
     # should check last paragraph for known headers.
     if line == "PR:": continue
     if line == "Submitted by:": continue
     if line == "Reviewed by:": continue
     if line == "Approved by:": continue
     if line == "Obtained from:": continue
     if line == "MFC after:": continue
     if line == "Relnotes:": continue
     if line == "Security:": continue
     if line == "Sponsored by:": continue
     s = s + line + "\n"
   s = s.rstrip() + "\n"
   return s
 
 
 def fix_txn(fs, txn_name):
   "Fix up the log message for txn TXN_NAME in FS.  See fix_log_message()."
   txn = svn.fs.svn_fs_open_txn(fs, txn_name)
   log_message = svn.fs.svn_fs_txn_prop(txn, "svn:log")
   if log_message is not None:
     new_message = fix_log_message(log_message)
+    if new_message.strip() == "":
+      sys.stderr.write("Log message required\n")
+      sys.exit(1)
     if new_message != log_message:
       svn.fs.svn_fs_change_txn_prop(txn, "svn:log", new_message)
+  else:
+    sys.stderr.write("Log message required\n")
+    sys.exit(1)
 
 
 def fix_rev(fs, revnum):
   "Fix up the log message for revision REVNUM in FS.  See fix_log_message()."
   log_message = svn.fs.svn_fs_revision_prop(fs, revnum, 'svn:log')
   if log_message is not None:
     new_message = fix_log_message(log_message)
     if new_message != log_message:
       svn.fs.svn_fs_change_rev_prop(fs, revnum, "svn:log", new_message)
 
 
 def usage_and_exit(error_msg=None):
   """Write usage information and exit.  If ERROR_MSG is provide, that
   error message is printed first (to stderr), the usage info goes to
   stderr, and the script exits with a non-zero status.  Otherwise,
   usage info goes to stdout and the script exits with a zero status."""
   import os.path
   stream = error_msg and sys.stderr or sys.stdout
   if error_msg:
     stream.write("ERROR: %s\n\n" % error_msg)
   stream.write("USAGE: %s [-t TXN_NAME | -r REV_NUM | --all-revs] REPOS\n"
                % (os.path.basename(sys.argv[0])))
   stream.write("""
 Ensure that log messages end with exactly one newline and no other
 whitespace characters.  Use as a pre-commit hook by passing '-t TXN_NAME';
 fix up a single revision by passing '-r REV_NUM'; fix up all revisions by
 passing '--all-revs'.  (When used as a pre-commit hook, may modify the
 svn:log property on the txn.)
 """)
   sys.exit(error_msg and 1 or 0)
 
 
 def main(ignored_pool, argv):
   repos_path = None
   txn_name = None
   rev_name = None
   all_revs = False
 
   try:
     opts, args = my_getopt(argv[1:], 't:r:h?', ["help", "all-revs"])
   except:
     usage_and_exit("problem processing arguments / options.")
   for opt, value in opts:
     if opt == '--help' or opt == '-h' or opt == '-?':
       usage_and_exit()
     elif opt == '-t':
       txn_name = value
     elif opt == '-r':
       rev_name = value
     elif opt == '--all-revs':
       all_revs = True
     else:
       usage_and_exit("unknown option '%s'." % opt)
 
   if txn_name is not None and rev_name is not None:
     usage_and_exit("cannot pass both -t and -r.")
   if txn_name is not None and all_revs:
     usage_and_exit("cannot pass --all-revs with -t.")
   if rev_name is not None and all_revs:
     usage_and_exit("cannot pass --all-revs with -r.")
   if rev_name is None and txn_name is None and not all_revs:
     usage_and_exit("must provide exactly one of -r, -t, or --all-revs.")
   if len(args) != 1:
     usage_and_exit("only one argument allowed (the repository).")
 
   repos_path = svn.core.svn_path_canonicalize(args[0])
 
   # A non-bindings version of this could be implemented by calling out
   # to 'svnlook getlog' and 'svnadmin setlog'.  However, using the
   # bindings results in much simpler code.
 
   fs = svn.repos.svn_repos_fs(svn.repos.svn_repos_open(repos_path))
   if txn_name is not None:
     fix_txn(fs, txn_name)
   elif rev_name is not None:
     fix_rev(fs, int(rev_name))
   elif all_revs:
     # Do it such that if we're running on a live repository, we'll
     # catch up even with commits that came in after we started.
     last_youngest = 0
     while True:
       youngest = svn.fs.svn_fs_youngest_rev(fs)
       if youngest >= last_youngest:
         for this_rev in range(last_youngest, youngest + 1):
           fix_rev(fs, this_rev)
         last_youngest = youngest + 1
       else:
         break
 
 
 if __name__ == '__main__':
   sys.exit(svn.core.run_app(main, sys.argv))