improve encoding handling for `setup.cfg`

Support the same mechanism as for Python sources for declaring
the encoding to be used when reading `setup.cfg` (see PEP 263),
and return the results of reading it as Unicode.

Fix #1062 and #1136.

1 files changed, 34 insertions, 0 deletions

diff --git a/setuptools/__init__.py b/setuptools/__init__.py
index 04f76740..77b4a374 100644
--- a/setuptools/__init__.py
+++ b/setuptools/__init__.py
@@ -4,9 +4,12 @@ import os
 import functools
 import distutils.core
 import distutils.filelist
+import re
+from distutils.errors import DistutilsOptionError
 from distutils.util import convert_path
 from fnmatch import fnmatchcase
 
+from setuptools.extern.six import string_types
 from setuptools.extern.six.moves import filter, map
 
 import setuptools.version
@@ -127,6 +130,37 @@ class Command(_Command):
         _Command.__init__(self, dist)
         vars(self).update(kw)
 
+    def _ensure_stringlike(self, option, what, default=None):
+        val = getattr(self, option)
+        if val is None:
+            setattr(self, option, default)
+            return default
+        elif not isinstance(val, string_types):
+            raise DistutilsOptionError("'%s' must be a %s (got `%s`)"
+                                       % (option, what, val))
+        return val
+
+    def ensure_string_list(self, option):
+        r"""Ensure that 'option' is a list of strings.  If 'option' is
+        currently a string, we split it either on /,\s*/ or /\s+/, so
+        "foo bar baz", "foo,bar,baz", and "foo,   bar baz" all become
+        ["foo", "bar", "baz"].
+        """
+        val = getattr(self, option)
+        if val is None:
+            return
+        elif isinstance(val, string_types):
+            setattr(self, option, re.split(r',\s*|\s+', val))
+        else:
+            if isinstance(val, list):
+                ok = all(isinstance(v, string_types) for v in val)
+            else:
+                ok = False
+            if not ok:
+                raise DistutilsOptionError(
+                      "'%s' must be a list of strings (got %r)"
+                      % (option, val))
+
     def reinitialize_command(self, command, reinit_subcommands=0, **kw):
         cmd = _Command.reinitialize_command(self, command, reinit_subcommands)
         vars(cmd).update(kw)