graft: skip ungraftable subtree copy and merge revisions

Summary:
Grafting subtree copy (branch) and merge commits doesn't seem particularly useful,
as grafting an O(1) copy commit could turn it into an O(n) operation. This diff skips
subtree copy and merge commits, similar to how merge commits are skipped.

Reviewed By: muirdm

Differential Revision: D67902937

fbshipit-source-id: 50b11c6dfaf97ec62d3de7fc96adab8641988b6f

eden/scm/sapling/commands/__init__.py

@@ -2598,6 +2598,16 @@ def _dograft(ui, repo, *revs, **opts):
     for rev in repo.revs("%ld and merge()", revs):
         ui.warn(_("skipping ungraftable merge revision %d\n") % rev)
         skipped.add(rev)
+    # check subtree copy and merge
+    for rev in revs:
+        if rev in skipped:
+            continue
+        ctx = repo[rev]
+        if subtreeutil.get_subtree_metadata(ctx.extra()):
+            ui.warn(
+                _("skipping ungraftable subtree copy and merge revision %s\n") % ctx
+            )
+            skipped.add(rev)
     revs = [r for r in revs if r not in skipped]
     if not revs:
         raise error.Abort(_("empty revision set was specified"))

eden/scm/tests/test-subtree-mutation.t

@@ -177,3 +177,30 @@ test split subtree copy commit
   $ hg split
   abort: cannot split subtree copy/merge commits
   [255]
+
+test graft subtree copy and merge commits
+  $ newclientrepo
+  $ drawdag <<'EOS'
+  > B  # B/foo/x = 1a\n2\n3\n
+  > |
+  > A  # A/foo/x = 1\n2\n3\n
+  > EOS
+  $ hg go -q $B
+  $ hg subtree copy -r $A --from-path foo --to-path bar -m "subtree copy foo to bar"
+  copying foo to bar
+  $ hg subtree merge -r $B --from-path foo --to-path bar -q
+  $ hg ci -m "subtree merge foo to bar"
+  $ hg log -G -T '{node|short} {desc|firstline}'
+  @  5d2f9c7b4852 subtree merge foo to bar
+  │
+  o  ee6785824a72 subtree copy foo to bar
+  │
+  o  c4fbbcdf676b B
+  │
+  o  b4cb27eee4e2 A
+  $ hg go -q $B
+  $ hg graft 5d2f9c7b4852 ee6785824a72
+  skipping ungraftable subtree copy and merge revision 5d2f9c7b4852
+  skipping ungraftable subtree copy and merge revision ee6785824a72
+  abort: empty revision set was specified
+  [255]