fix(config): ignore empty values in config file

Similar to git, we now ignore options which have no value.
Previously it would not handle it consistently, and throw a parsing
error the first time the cache was built.

Afterwards, it was fully usable though.
Now we specifically check for the case of no-value options instead.

Closes #349

Author: Byron

git/config.py

@@ -156,15 +156,21 @@ class GitConfigParser(with_metaclass(MetaParserBuilder, cp.RawConfigParser, obje
 
     #} END configuration
 
+    optvalueonly_source = r'\s*(?P<option>[^:=\s][^:=]*)'
+
+    OPTVALUEONLY = re.compile(optvalueonly_source)
+
     OPTCRE = re.compile(
-        r'\s*(?P<option>[^:=\s][^:=]*)'       # very permissive, incuding leading whitespace
-        r'\s*(?P<vi>[:=])\s*'                 # any number of space/tab,
+        optvalueonly_source                          # very permissive, incuding leading whitespace
+        + r'\s*(?P<vi>[:=])\s*'               # any number of space/tab,
                                               # followed by separator
                                               # (either : or =), followed
                                               # by any # space/tab
-        r'(?P<value>.*)$'                     # everything up to eol
+        + r'(?P<value>.*)$'                     # everything up to eol
     )
 
+    del optvalueonly_source
+
     # list of RawConfigParser methods able to change the instance
     _mutating_methods_ = ("add_section", "remove_section", "remove_option", "set")
 
@@ -322,9 +328,11 @@ def string_decode(v):
                     # end handle multi-line
                     cursect[optname] = optval
                 else:
-                    if not e:
-                        e = cp.ParsingError(fpname)
-                    e.append(lineno, repr(line))
+                    # check if it's an option with no value - it's just ignored by git
+                    if not self.OPTVALUEONLY.match(line):
+                        if not e:
+                            e = cp.ParsingError(fpname)
+                        e.append(lineno, repr(line))
                     continue
             else:
                 line = line.rstrip()

git/test/fixtures/git_config_with_empty_value

@@ -0,0 +1,4 @@
+[color]
+	ui
+[core]
+	filemode = true

git/test/test_config.py

@@ -210,3 +210,10 @@ def test_complex_aliases(self):
         self.assertEqual(w_config.get('alias', 'rbi'), '"!g() { git rebase -i origin/${1:-master} ; } ; g"')
         w_config.release()
         self.assertEqual(file_obj.getvalue(), self._to_memcache(fixture_path('.gitconfig')).getvalue())
+
+    def test_empty_config_value(self):
+        cr = GitConfigParser(fixture_path('git_config_with_empty_value'), read_only=True)
+
+        assert cr.get_value('core', 'filemode'), "Should read keys with values"
+
+        self.failUnlessRaises(cp.NoOptionError, cr.get_value, 'color', 'ui')