extensions: catch OSError when hgext is not accessible (issue1708)

Temporary workaround for issue1708: on win32 with py2exe, hgext is distributed
inside a zipped file (which anyway does not contain the py files from which we
ought to extract the documentation strings), which raises a WindowsError
(subclasses OSError).

This means that on such platforms the list of disabled extensions won't be
available. Real fix postponed for after Mercurial 1.3.

mercurial/extensions.py

@@ -1,177 +1,182
 # extensions.py - extension handling for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
 import imp, os
 import util, cmdutil, help
 from i18n import _, gettext
 
 _extensions = {}
 _order = []
 
 def extensions():
     for name in _order:
         module = _extensions[name]
         if module:
             yield name, module
 
 def find(name):
     '''return module with given extension name'''
     try:
         return _extensions[name]
     except KeyError:
         for k, v in _extensions.iteritems():
             if k.endswith('.' + name) or k.endswith('/' + name):
                 return v
         raise KeyError(name)
 
 def loadpath(path, module_name):
     module_name = module_name.replace('.', '_')
     path = os.path.expanduser(path)
     if os.path.isdir(path):
         # module/__init__.py style
         d, f = os.path.split(path.rstrip('/'))
         fd, fpath, desc = imp.find_module(f, [d])
         return imp.load_module(module_name, fd, fpath, desc)
     else:
         return imp.load_source(module_name, path)
 
 def load(ui, name, path):
     if name.startswith('hgext.') or name.startswith('hgext/'):
         shortname = name[6:]
     else:
         shortname = name
     if shortname in _extensions:
         return
     _extensions[shortname] = None
     if path:
         # the module will be loaded in sys.modules
         # choose an unique name so that it doesn't
         # conflicts with other modules
         mod = loadpath(path, 'hgext.%s' % name)
     else:
         def importh(name):
             mod = __import__(name)
             components = name.split('.')
             for comp in components[1:]:
                 mod = getattr(mod, comp)
             return mod
         try:
             mod = importh("hgext.%s" % name)
         except ImportError:
             mod = importh(name)
     _extensions[shortname] = mod
     _order.append(shortname)
 
     uisetup = getattr(mod, 'uisetup', None)
     if uisetup:
         uisetup(ui)
 
 def loadall(ui):
     result = ui.configitems("extensions")
     for (name, path) in result:
         if path:
             if path[0] == '!':
                 continue
         try:
             load(ui, name, path)
         except KeyboardInterrupt:
             raise
         except Exception, inst:
             if path:
                 ui.warn(_("*** failed to import extension %s from %s: %s\n")
                         % (name, path, inst))
             else:
                 ui.warn(_("*** failed to import extension %s: %s\n")
                         % (name, inst))
             if ui.traceback():
                 return 1
 
 def wrapcommand(table, command, wrapper):
     aliases, entry = cmdutil.findcmd(command, table)
     for alias, e in table.iteritems():
         if e is entry:
             key = alias
             break
 
     origfn = entry[0]
     def wrap(*args, **kwargs):
         return util.checksignature(wrapper)(
             util.checksignature(origfn), *args, **kwargs)
 
     wrap.__doc__ = getattr(origfn, '__doc__')
     wrap.__module__ = getattr(origfn, '__module__')
 
     newentry = list(entry)
     newentry[0] = wrap
     table[key] = tuple(newentry)
     return entry
 
 def wrapfunction(container, funcname, wrapper):
     def wrap(*args, **kwargs):
         return wrapper(origfn, *args, **kwargs)
 
     origfn = getattr(container, funcname)
     setattr(container, funcname, wrap)
     return origfn
 
 def disabled():
     '''find disabled extensions from hgext
     returns a dict of {name: desc}, and the max name length'''
 
     import hgext
     extpath = os.path.dirname(os.path.abspath(hgext.__file__))
 
+    try: # might not be a filesystem path
+        files = os.listdir(extpath)
+    except OSError:
+        return None, 0
+
     exts = {}
     maxlength = 0
-    for e in os.listdir(extpath):
+    for e in files:
 
         if e.endswith('.py'):
             name = e.rsplit('.', 1)[0]
             path = os.path.join(extpath, e)
         else:
             name = e
             path = os.path.join(extpath, e, '__init__.py')
             if not os.path.exists(path):
                 continue
 
         if name in exts or name in _order or name == '__init__':
             continue
 
         try:
             file = open(path)
         except IOError:
             continue
         else:
             doc = help.moduledoc(file)
             file.close()
 
         if doc: # extracting localized synopsis
             exts[name] = gettext(doc).splitlines()[0]
         else:
             exts[name] = _('(no help text available)')
 
         if len(name) > maxlength:
             maxlength = len(name)
 
     return exts, maxlength
 
 def enabled():
     '''return a dict of {name: desc} of extensions, and the max name length'''
 
     if not enabled:
         return {}, 0
 
     exts = {}
     maxlength = 0
     exthelps = []
     for ename, ext in extensions():
         doc = (gettext(ext.__doc__) or _('(no help text available)'))
         ename = ename.split('.')[-1]
         maxlength = max(len(ename), maxlength)
         exts[ename] = doc.splitlines(0)[0].strip()
 
     return exts, maxlength