[PATCH 00 of 13] Cleanup of the purge extension

[Alexis S. L. Carvalho]

Sorry for the huge latency...

Thus spake Emanuele Aina:
> Alexis S. L. Carvalho evidenziò:
> >>>I'd really like to put at least some safety net before moving purge.py
> >>>to hgext.
> >>What kind of safety net?
> >
> >For example, refusing to run if there are missing files (I think it
> >should be enough, if we assume that the filesystem doesn't return 2
> >aliases to the same file[1] on a single os.listdir - which I hope is not
> >much to ask...  But I wouldn't mind somebody thinking a bit more about
> >this).
> >
> >Maybe this could be done only for name-mangling filesystems.  And we
> >probably could use a --force flag to allow users to shoot their feet.
> 
> Do you think that this code will be enough?
> 
> if missing and not (util.checkfolding(repo.wjoin('.hg/Foo') or force):
>     util.Abort("purging on name mangling fs is not yet fully supported")

Well, that could be a simpler "util.checkfolding(repo.path)".

But I think I'm leaning towards something like trying to lstat every
missing file.  If we find any of them, abort (unconditionally).
Otherwise, abort if --force was not specified.  Something like
this (completely untested):

found = []
for f in missing:
    try:
        os.lstat(f)
    except OSError, inst:
        if inst.errno != errno.ENOENT:
            raise
        continue
    found.append(f)

if found:
    if not ui.quiet:
        ui.warn(_("The following tracked files weren't listed by the "
	          "filesystem, but could still be found:\n"))
        for f in found:
            ui.warn("%s\n" % f)
	ui.warn(_("Is this a case-insensitive filesystem?\n"))
    raise util.Abort(_("purging on name mangling filesystems is not "
                       "yet fully supported"))

if missing and not force:
    raise util.Abort(_("some nice message that mentions missing files "
                       "and --force"))

I think that should be safe enough - we really want to abort in the
"if found:" case; OTOH the second conditional is probably not strictly
necessary.

Alexis