# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 1513721881 28800
# Node ID 910f56f0d09c929c2c50e065e23db474eedaf623
# Parent  ddfd60760fac565bc3ca6b8beedcf9ea90d8d142
revset: make "fromsvn()" lazy

"fromsvn()" could be a huge revset. Therefore a lazy version makes more
sense.  This also resolves a subtle ordering issue.  See
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-August/103368.html
for the context.

diff --git a/hgsubversion/util.py b/hgsubversion/util.py
--- a/hgsubversion/util.py
+++ b/hgsubversion/util.py
@@ -348,17 +348,13 @@ def revset_fromsvn(repo, subset, x):
     '''
     args = revset.getargs(x, 0, 0, "fromsvn takes no arguments")
 
-    rev = repo.changelog.rev
-    bin = node.bin
     meta = repo.svnmeta(skiperrorcheck=True)
     if not meta.revmapexists:
         raise hgutil.Abort("svn metadata is missing - "
                            "run 'hg svn rebuildmeta' to reconstruct it")
-    svnrevs = set(rev(h) for h in meta.revmap.hashes().keys())
-    filteredrevs = filter(svnrevs.__contains__, subset)
-    if smartset is not None:
-        filteredrevs = smartset.baseset(filteredrevs)
-    return filteredrevs
+    tonode = repo.changelog.node
+    hashes = meta.revmap.hashes()
+    return subset.filter(lambda r: tonode(r) in hashes)
 
 def revset_svnrev(repo, subset, x):
     '''``svnrev(number)``