convert: add a mode where mercurial_sink skips empty revisions.
The getchanges function of some converter_source classes can return
some false positives. I.e. they sometimes claim that a file "foo"
was changed in some revision, even though its contents are still the
same.
convert_svn is particularly bad, but I think this can also happen with
convert_cvs and, at least in theory, with mercurial_source.
For regular conversions this is not really a problem - as long as
getfile returns the right contents, we'll get a converted revision
with the right contents. But when we use --filemap, this could lead
to superfluous revisions being converted.
Instead of fixing every converter_source, I decided to change
mercurial_sink to work around this problem.
When --filemap is used, we're interested only in revisions that touch
some specific files. If a revision doesn't change any of these files,
then we're not interested in it (at least for revisions with a single
parent; merges are special).
For mercurial_sink, we abuse this property and rollback a commit if
the manifest text hasn't changed. This avoids duplicating the logic
from localrepo.filecommit to detect unchanged files.
#!/usr/bin/env python
from mercurial import demandimport
demandimport.enable()
import re
rsub = re.sub
def f(obj):
l = repr(obj)
l = rsub("0x[0-9a-fA-F]+", "0x?", l)
l = rsub("from '.*'", "from '?'", l)
return l
import os
print "os =", f(os)
print "os.system =", f(os.system)
print "os =", f(os)
import mercurial.version
print "mercurial.version =", f(mercurial.version)
print "mercurial.version.get_version =", f(mercurial.version.get_version)
print "mercurial.version =", f(mercurial.version)
print "mercurial =", f(mercurial)
from mercurial import util
print "util =", f(util)
print "util.system =", f(util.system)
print "util =", f(util)
print "util.system =", f(util.system)
import re as fred
print "fred =", f(fred)
import sys as re
print "re =", f(re)
print "fred =", f(fred)
print "fred.sub =", f(fred.sub)
print "fred =", f(fred)
print "re =", f(re)
print "re.stdout =", f(re.stdout)
print "re =", f(re)