vfs: give all vfs an options attribute by default

Multiple code path assume vfs have an options attribute, including the vfs module
itself. So for consistency we explicitly add one to all vfs.

This will prevent various crash in the next changesets.

Differential Revision: https://phab.mercurial-scm.org/D6935

contrib/dumprevlog

@@ -22,6 +22,7 b" def binopen(path, mode=b'rb'):"
     if b'b' not in mode:
         mode = mode + b'b'
     return open(path, pycompat.sysstr(mode))
+binopen.options = {}
 
 def printb(data, end=b'\n'):
     sys.stdout.flush()

mercurial/revlog.py

@@ -355,7 +355,7 b' class revlog(object):'
 
     def _loadindex(self):
         mmapindexthreshold = None
-        opts = getattr(self.opener, 'options', {}) or {}
+        opts = self.opener.options
 
         if 'revlogv2' in opts:
             newversionflags = REVLOGV2 | FLAG_INLINE_DATA
@@ -363,7 +363,7 b' class revlog(object):'
             newversionflags = REVLOGV1 | FLAG_INLINE_DATA
             if 'generaldelta' in opts:
                 newversionflags |= FLAG_GENERALDELTA
-        elif 'revlogv0' in getattr(self.opener, 'options', {}):
+        elif 'revlogv0' in self.opener.options:
             newversionflags = REVLOGV0
         else:
             newversionflags = REVLOG_DEFAULT_VERSION

mercurial/statichttprepo.py

@@ -115,6 +115,7 b' def build_opener(ui, authinfo):'
     class statichttpvfs(vfsmod.abstractvfs):
         def __init__(self, base):
             self.base = base
+            self.options = {}
 
         def __call__(self, path, mode='r', *args, **kw):
             if mode not in ('r', 'rb'):

mercurial/vfs.py

@@ -327,6 +327,7 b' class vfs(abstractvfs):'
             self.audit = (lambda path, mode=None: True)
         self.createmode = None
         self._trustnlink = None
+        self.options = {}
 
     @util.propertycache
     def _cansymlink(self):

tests/test-parseindex.t

@@ -53,6 +53,7 b' We approximate that by reducing the read'
   >     def wrapper(*a, **kwargs):
   >         f = o(*a, **kwargs)
   >         return singlebyteread(f)
+  >     wrapper.options = o.options
   >     return wrapper
   > 
   > cl = changelog.changelog(opener(b'.hg/store'))