config: discard "%unset" values defined in the other files read in previously

Before this patch, "%unset" can't unset values defined in the other
files read in previously, even though online help document says that
it can. It can unset only values defined in the same configuration
file.

For example, the value defined in "~/.hgrc" can't be unset by "%unset"
in ".hg/hgrc" of the repository.

This patch records "%unset"-ed values in "config.parse()", and
discards corresponding values in "config.update()".

mercurial/config.py

@@ -1,183 +1,189 b''
 # config.py - configuration parsing for Mercurial
 #
 #  Copyright 2009 Matt Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from i18n import _
 import error, util
 import os, errno
 
 class sortdict(dict):
     'a simple sorted dictionary'
     def __init__(self, data=None):
         self._list = []
         if data:
             self.update(data)
     def copy(self):
         return sortdict(self)
     def __setitem__(self, key, val):
         if key in self:
             self._list.remove(key)
         self._list.append(key)
         dict.__setitem__(self, key, val)
     def __iter__(self):
         return self._list.__iter__()
     def update(self, src):
         for k in src:
             self[k] = src[k]
     def clear(self):
         dict.clear(self)
         self._list = []
     def items(self):
         return [(k, self[k]) for k in self._list]
     def __delitem__(self, key):
         dict.__delitem__(self, key)
         self._list.remove(key)
     def keys(self):
         return self._list
     def iterkeys(self):
         return self._list.__iter__()
 
 class config(object):
     def __init__(self, data=None):
         self._data = {}
         self._source = {}
+        self._unset = []
         if data:
             for k in data._data:
                 self._data[k] = data[k].copy()
             self._source = data._source.copy()
     def copy(self):
         return config(self)
     def __contains__(self, section):
         return section in self._data
     def __getitem__(self, section):
         return self._data.get(section, {})
     def __iter__(self):
         for d in self.sections():
             yield d
     def update(self, src):
+        for s, n in src._unset:
+            if s in self and n in self._data[s]:
+                del self._data[s][n]
+                del self._source[(s, n)]
         for s in src:
             if s not in self:
                 self._data[s] = sortdict()
             self._data[s].update(src._data[s])
         self._source.update(src._source)
     def get(self, section, item, default=None):
         return self._data.get(section, {}).get(item, default)
 
     def backup(self, section, item):
         """return a tuple allowing restore to reinstall a previous value
 
         The main reason we need it is because it handles the "no data" case.
         """
         try:
             value = self._data[section][item]
             source = self.source(section, item)
             return (section, item, value, source)
         except KeyError:
             return (section, item)
 
     def source(self, section, item):
         return self._source.get((section, item), "")
     def sections(self):
         return sorted(self._data.keys())
     def items(self, section):
         return self._data.get(section, {}).items()
     def set(self, section, item, value, source=""):
         if section not in self:
             self._data[section] = sortdict()
         self._data[section][item] = value
         self._source[(section, item)] = source
 
     def restore(self, data):
         """restore data returned by self.backup"""
         if len(data) == 4:
             # restore old data
             section, item, value, source = data
             self._data[section][item] = value
             self._source[(section, item)] = source
         else:
             # no data before, remove everything
             section, item = data
             if section in self._data:
                 del self._data[section][item]
             self._source.pop((section, item), None)
 
     def parse(self, src, data, sections=None, remap=None, include=None):
         sectionre = util.compilere(r'\[([^\[]+)\]')
         itemre = util.compilere(r'([^=\s][^=]*?)\s*=\s*(.*\S|)')
         contre = util.compilere(r'\s+(\S|\S.*\S)\s*$')
         emptyre = util.compilere(r'(;|#|\s*$)')
         commentre = util.compilere(r'(;|#)')
         unsetre = util.compilere(r'%unset\s+(\S+)')
         includere = util.compilere(r'%include\s+(\S|\S.*\S)\s*$')
         section = ""
         item = None
         line = 0
         cont = False
 
         for l in data.splitlines(True):
             line += 1
             if line == 1 and l.startswith('\xef\xbb\xbf'):
                 # Someone set us up the BOM
                 l = l[3:]
             if cont:
                 if commentre.match(l):
                     continue
                 m = contre.match(l)
                 if m:
                     if sections and section not in sections:
                         continue
                     v = self.get(section, item) + "\n" + m.group(1)
                     self.set(section, item, v, "%s:%d" % (src, line))
                     continue
                 item = None
                 cont = False
             m = includere.match(l)
             if m:
                 inc = util.expandpath(m.group(1))
                 base = os.path.dirname(src)
                 inc = os.path.normpath(os.path.join(base, inc))
                 if include:
                     try:
                         include(inc, remap=remap, sections=sections)
                     except IOError, inst:
                         if inst.errno != errno.ENOENT:
                             raise error.ParseError(_("cannot include %s (%s)")
                                                    % (inc, inst.strerror),
                                                    "%s:%s" % (src, line))
                 continue
             if emptyre.match(l):
                 continue
             m = sectionre.match(l)
             if m:
                 section = m.group(1)
                 if remap:
                     section = remap.get(section, section)
                 if section not in self:
                     self._data[section] = sortdict()
                 continue
             m = itemre.match(l)
             if m:
                 item = m.group(1)
                 cont = True
                 if sections and section not in sections:
                     continue
                 self.set(section, item, m.group(2), "%s:%d" % (src, line))
                 continue
             m = unsetre.match(l)
             if m:
                 name = m.group(1)
                 if sections and section not in sections:
                     continue
                 if self.get(section, name) is not None:
                     del self._data[section][name]
+                self._unset.append((section, name))
                 continue
 
             raise error.ParseError(l.rstrip(), ("%s:%s" % (src, line)))
 
     def read(self, path, fp=None, sections=None, remap=None):
         if not fp:
             fp = util.posixfile(path)
         self.parse(path, fp.read(), sections, remap, self.read)

tests/test-config.t

@@ -1,13 +1,44 b''
 hide outer repo
   $ hg init
 
 Test case sensitive configuration
 
   $ echo '[Section]' >> $HGRCPATH
   $ echo 'KeY = Case Sensitive' >> $HGRCPATH
   $ echo 'key = lower case' >> $HGRCPATH
 
   $ hg showconfig Section
   Section.KeY=Case Sensitive
   Section.key=lower case
 
+Test "%unset"
+
+  $ cat >> $HGRCPATH <<EOF
+  > [unsettest]
+  > local-hgrcpath = should be unset (HGRCPATH)
+  > %unset local-hgrcpath
+  > 
+  > global = should be unset (HGRCPATH)
+  > 
+  > both = should be unset (HGRCPATH)
+  > 
+  > set-after-unset = should be unset (HGRCPATH)
+  > EOF
+
+  $ cat >> .hg/hgrc <<EOF
+  > [unsettest]
+  > local-hgrc = should be unset (.hg/hgrc)
+  > %unset local-hgrc
+  > 
+  > %unset global
+  > 
+  > both = should be unset (.hg/hgrc)
+  > %unset both
+  > 
+  > set-after-unset = should be unset (.hg/hgrc)
+  > %unset set-after-unset
+  > set-after-unset = should be set (.hg/hgrc)
+  > EOF
+
+  $ hg showconfig unsettest
+  unsettest.set-after-unset=should be set (.hg/hgrc)