calling "annotate --show-ids" for an empty file leads to an exception

[Anne Mohsen]

Bazaar version used :

Bazaar (bzr) 1.11dev
  from bzr checkout /home/mysql_src/logiciels/bzr_versions/dev
    revision: 3923
    revid: <email address hidden>
    branch nick: dev

Steps to reproduce:

bzr init
touch bar
bzr add bar
bzr commit -m bar
bzr annotate --show-ids bar

Traceback (most recent call last):

  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/commands.py", line 893, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/commands.py", line 839, in run_bzr
    ret = run(*run_argv)
  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/commands.py", line 539, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/commands.py", line 853, in ignore_pipe
    result = func(*args, **kwargs)
  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/builtins.py", line 3708, in run
    show_ids=show_ids)
  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/annotate.py", line 91, in annotate_file_tree
    return _show_id_annotations(annotations, to_file, full)
  File "/home/mysql_src/logiciels/bzr_versions/dev/bzrlib/annotate.py", line 155, in _show_id_annotations
    max_origin_len = max(len(origin) for origin, text in annotations)
ValueError: max() arg is an empty sequence

A way to correct it is to add in annotate.py :

--- bzrlib/annotate.py 2008-09-02 01:26:52 +0000
+++ bzrlib/annotate.py 2009-01-06 21:31:53 +0000
@@ -151,6 +151,8 @@

 def _show_id_annotations(annotations, to_file, full):
+ if not annotations:
+ return
     last_rev_id = None
     max_origin_len = max(len(origin) for origin, text in annotations)
     for origin, text in annotations:

[Martin Pool (mbp)]

  status confirmed
  importance high
  tags mysql patch
  assigned me

--
Martin <http://launchpad.net/~mbp>

[Robert Collins (lifeless)]

 status confirmed

Looks like a solid fix to me. A test would be ideal.

-Rob

[Anne Mohsen (anne-mohsen)]

I am attaching a patch with the fix and a test.