Fix $(dirname) for roslaunch-check.

[mikepurvis]

Small fix for using $(dirname) in launch files covered by the roslaunch-check tests. Currently you get the test failing with a traceback like this:

Traceback (most recent call last):
  File "<ws>/share/roslaunch/scripts/roslaunch-check", line 90, in <module>
    error_msg = check_roslaunch_file(roslaunch_path, use_test_depends=options.test_depends)
  File "<ws>/share/roslaunch/scripts/roslaunch-check", line 47, in check_roslaunch_file
    error_msg = roslaunch.rlutil.check_roslaunch(roslaunch_file, use_test_depends=use_test_depends)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/rlutil.py", line 201, in check_roslaunch
    base_pkg, file_deps, missing = roslaunch.depends.roslaunch_deps([f], use_test_depends=use_test_depends)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/depends.py", line 332, in roslaunch_deps
    rl_file_deps(file_deps, launch_file, verbose)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/depends.py", line 226, in rl_file_deps
    parse_launch(launch_file, file_deps, verbose)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/depends.py", line 211, in parse_launch
    _parse_launch(launch_tag.childNodes, launch_file, file_deps, verbose, context)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/depends.py", line 141, in _parse_launch
    sub_launch_file = resolve_args(tag.attributes['file'].value, context)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/substitution_args.py", line 389, in resolve_args
    resolved = _resolve_args(arg_str, context, resolve_anon, commands)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/substitution_args.py", line 407, in _resolve_args
    resolved = commands[command](resolved, a, args, context)
  File "<ws>/lib/python2.7/dist-packages/roslaunch/substitution_args.py", line 136, in _dirname
    return resolved.replace("$(%s)" % a, _eval_dirname(context.get('filename', None)))
  File "<ws>/lib/python2.7/dist-packages/roslaunch/substitution_args.py", line 125, in _eval_dirname
    raise SubstitutionException("Cannot substitute $(dirname), no file/directory information available.")
roslaunch.substitution_args.SubstitutionException: Cannot substitute $(dirname), no file/directory information available.

The file/directory information it's referring to comes in via xmlloader, here:

ros_comm/tools/roslaunch/src/roslaunch/xmlloader.py

Lines 181 to 191 in acd8313

	def resolve_args(self, args, context):
	"""
	Wrapper around substitution_args.resolve_args to set common parameters
	"""
	# resolve_args gets called a lot, so we optimize by testing for dollar sign before resolving
	if args and '$' in args:
	# Populate resolve_dict with name of the current file being processed.
	context.resolve_dict['filename'] = context.filename
	return substitution_args.resolve_args(args, context=context.resolve_dict, resolve_anon=self.resolve_anon)
	else:
	return args

However, roslaunch-check bypasses this logic so the context value never gets set. This change corrects that.

[dirk-thomas]

Thanks for the patch.