svn: fix subprocess problems on some of the calls for file checking.

vcsserver/svn.py

@@ -38,6 +38,7 b' import svn.repos'
 from vcsserver import svn_diff, exceptions, subprocessio, settings
 from vcsserver.base import RepoFactory, raise_from_original, ArchiveNode, archive_repo
 from vcsserver.exceptions import NoContentException
+from vcsserver.utils import safe_str
 from vcsserver.vcs_base import RemoteBase
 
 log = logging.getLogger(__name__)
@@ -483,9 +484,7 b' class SvnRemote(RemoteBase):'
         if path and os.path.isdir(path):
             opts['cwd'] = path
 
-        safe_call = False
-        if '_safe' in opts:
-            safe_call = True
+        safe_call = opts.pop('_safe', False)
 
         svnenv = os.environ.copy()
         svnenv.update(opts.pop('extra_env', {}))
@@ -499,7 +498,7 b' class SvnRemote(RemoteBase):'
             return ''.join(p), ''.join(p.error)
         except (EnvironmentError, OSError) as err:
             if safe_call:
-                return '', err
+                return '', safe_str(err).strip()
             else:
                 cmd = ' '.join(cmd)  # human friendly CMD
                 tb_err = ("Couldn't run svn command (%s).\n"