rebase: ensure rebase does not revive extinct revision

Here, we exclude hidden changesets from a rebase operation. If we
don't, a rewritten version of the hidden changesets will be created
by rebase. Those rewritten versions won't be hidden and will likely
conflict with other rewriting or revive pruned changeset. Moreover,
rewriting hidden revisions will surprise the user.

This change would not be necessary if changelog filtering were
already in core. But it's fairly cheap and helps to increase the
test-suite for such filtering.

Once changelog level filtering is added, hidden changes will be
automatically excluded or included according to the global --hidden
flags. Plain ignoring them is good enough for now.

hgext/rebase.py

@@ -184,7 +184,8 b' def rebase(ui, repo, **opts):'
                 rebaseset = repo.revs(
                     '(children(ancestor(%ld, %d)) and ::(%ld))::',
                     base, dest, base)
-
+            # temporary top level filtering of extinct revisions
+            rebaseset = repo.revs('%ld - hidden()', rebaseset)
             if rebaseset:
                 root = min(rebaseset)
             else:
@@ -193,7 +194,7 b' def rebase(ui, repo, **opts):'
             if not rebaseset:
                 repo.ui.debug('base is ancestor of destination\n')
                 result = None
-            elif not keepf and repo.revs('first(children(%ld) - %ld)',
+            elif not keepf and repo.revs('first(children(%ld) - %ld)-hidden()',
                                          rebaseset, rebaseset):
                 raise util.Abort(
                     _("can't remove original changesets with"

tests/test-rebase-obsolete.t

@@ -222,3 +222,61 b' collapse rebase'
 
   $ cd ..
 
+Rebase set has hidden descendants
+---------------------------------
+
+We rebase a changeset which has a hidden changeset. The hidden changeset must
+not be rebased.
+
+  $ hg clone base hidden
+  updating to branch default
+  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cd hidden
+  $ hg rebase -s 5fddd98957c8 -d eea13746799a
+  $ hg rebase -s 42ccdea3bb16 -d 02de42196ebe
+  $ hg log -G
+  @  10:7c6027df6a99 B
+  |
+  | o  9:cf44d2f5a9f4 D
+  | |
+  | o  8:e273c5e7d2d2 C
+  | |
+  o |  7:02de42196ebe H
+  | |
+  | o  6:eea13746799a G
+  |/|
+  o |  5:24b6387c8c8c F
+  | |
+  | o  4:9520eea781bc E
+  |/
+  o  0:cd010b8cd998 A
+  
+  $ hg log --hidden -G
+  @  10:7c6027df6a99 B
+  |
+  | o  9:cf44d2f5a9f4 D
+  | |
+  | o  8:e273c5e7d2d2 C
+  | |
+  o |  7:02de42196ebe H
+  | |
+  | o  6:eea13746799a G
+  |/|
+  o |  5:24b6387c8c8c F
+  | |
+  | o  4:9520eea781bc E
+  |/
+  | x  3:32af7686d403 D
+  | |
+  | x  2:5fddd98957c8 C
+  | |
+  | x  1:42ccdea3bb16 B
+  |/
+  o  0:cd010b8cd998 A
+  
+  $ hg debugobsolete
+  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b e273c5e7d2d29df783dce9f9eaa3ac4adc69c15d 0 {'date': '*', 'user': 'test'} (glob)
+  32af7686d403cf45b5d95f2d70cebea587ac806a cf44d2f5a9f4297a62be94cbdd3dff7c7dc54258 0 {'date': '*', 'user': 'test'} (glob)
+  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 7c6027df6a99d93f461868e5433f63bde20b6dfb 0 {'date': '*', 'user': 'test'} (glob)
+
+  $ cd ..