exceptions: improve handling of exception that are unhandled.

- inject traceback information into unhandled exceptions.

rhodecode/lib/vcs/exceptions.py

@@ -1,201 +1,210 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2014-2017 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 """
 Custom vcs exceptions module.
 """
 
 import functools
 import urllib2
 
 
 class VCSCommunicationError(Exception):
     pass
 
 
 class HttpVCSCommunicationError(VCSCommunicationError):
     pass
 
 
 class VCSError(Exception):
     pass
 
 
 class RepositoryError(VCSError):
     pass
 
 
 class RepositoryRequirementError(RepositoryError):
     pass
 
 
 class VCSBackendNotSupportedError(VCSError):
     """
     Exception raised when VCSServer does not support requested backend
     """
 
 
 class EmptyRepositoryError(RepositoryError):
     pass
 
 
 class TagAlreadyExistError(RepositoryError):
     pass
 
 
 class TagDoesNotExistError(RepositoryError):
     pass
 
 
 class BranchAlreadyExistError(RepositoryError):
     pass
 
 
 class BranchDoesNotExistError(RepositoryError):
     pass
 
 
 class CommitError(RepositoryError):
     """
     Exceptions related to an existing commit
     """
 
 
 class CommitDoesNotExistError(CommitError):
     pass
 
 
 class CommittingError(RepositoryError):
     """
     Exceptions happening while creating a new commit
     """
 
 
 class NothingChangedError(CommittingError):
     pass
 
 
 class NodeError(VCSError):
     pass
 
 
 class RemovedFileNodeError(NodeError):
     pass
 
 
 class NodeAlreadyExistsError(CommittingError):
     pass
 
 
 class NodeAlreadyChangedError(CommittingError):
     pass
 
 
 class NodeDoesNotExistError(CommittingError):
     pass
 
 
 class NodeNotChangedError(CommittingError):
     pass
 
 
 class NodeAlreadyAddedError(CommittingError):
     pass
 
 
 class NodeAlreadyRemovedError(CommittingError):
     pass
 
 
 class SubrepoMergeError(RepositoryError):
     """
     This happens if we try to merge a repository which contains subrepos and
     the subrepos cannot be merged. The subrepos are not merged itself but
     their references in the root repo are merged.
     """
 
 
 class ImproperArchiveTypeError(VCSError):
     pass
 
 
 class CommandError(VCSError):
     pass
 
 
 class UnhandledException(VCSError):
     """
     Signals that something unexpected went wrong.
 
     This usually means we have a programming error on the side of the VCSServer
     and should inspect the logfile of the VCSServer to find more details.
     """
 
 
 _EXCEPTION_MAP = {
     'abort': RepositoryError,
     'archive': ImproperArchiveTypeError,
     'error': RepositoryError,
     'lookup': CommitDoesNotExistError,
     'repo_locked': RepositoryError,
     'requirement': RepositoryRequirementError,
     'unhandled': UnhandledException,
     # TODO: johbo: Define our own exception for this and stop abusing
     # urllib's exception class.
     'url_error': urllib2.URLError,
     'subrepo_merge_error': SubrepoMergeError,
 }
 
 
 def map_vcs_exceptions(func):
     """
     Utility to decorate functions so that plain exceptions are translated.
 
     The translation is based on `exc_map` which maps a `str` indicating
     the error type into an exception class representing this error inside
     of the vcs layer.
     """
 
     @functools.wraps(func)
     def wrapper(*args, **kwargs):
         try:
             return func(*args, **kwargs)
         except Exception as e:
             # The error middleware adds information if it finds
             # __traceback_info__ in a frame object. This way the remote
             # traceback information is made available in error reports.
             remote_tb = getattr(e, '_vcs_server_traceback', None)
+            __traceback_info__ = None
             if remote_tb:
+                if isinstance(remote_tb, basestring):
+                    remote_tb = [remote_tb]
                 __traceback_info__ = (
                     'Found VCSServer remote traceback information:\n\n' +
                     '\n'.join(remote_tb))
 
                 # Avoid that remote_tb also appears in the frame
                 del remote_tb
 
             # Special vcs errors had an attribute "_vcs_kind" which is used
             # to translate them to the proper exception class in the vcs
             # client layer.
             kind = getattr(e, '_vcs_kind', None)
+
             if kind:
-                raise _EXCEPTION_MAP[kind](*e.args)
+                if any(e.args):
+                    args = e.args
+                else:
+                    args = [__traceback_info__ or 'unhandledException']
+
+                raise _EXCEPTION_MAP[kind](*args)
             else:
                 raise
     return wrapper