rebase: fix bug that caused transitive copy records to disappear (issue4192)

The defect was that copies were always duplicated against the target
revision, rather than the first parent of the revision being
rebased. This produced nominally correct results if changes were
rebased one at a time (or with --collapse), but was wrong if we
rebased a sequence of changesets which contained a sequence of copies.

hgext/rebase.py

@@ -345,7 +345,16 b' def rebase(ui, repo, **opts):'
                                   'resolve, then hg rebase --continue)'))
                     finally:
                         ui.setconfig('ui', 'forcemerge', '', 'rebase')
-                cmdutil.duplicatecopies(repo, rev, target)
+                if collapsef:
+                    cmdutil.duplicatecopies(repo, rev, target)
+                else:
+                    # If we're not using --collapse, we need to
+                    # duplicate copies between the revision we're
+                    # rebasing and its first parent, but *not*
+                    # duplicate any copies that have already been
+                    # performed in the destination.
+                    p1rev = repo[rev].p1().rev()
+                    cmdutil.duplicatecopies(repo, rev, p1rev, skiprev=target)
                 if not collapsef:
                     newrev = concludenode(repo, rev, p1, p2, extrafn=extrafn,
                                           editor=editor)

tests/test-rebase-rename.t

@@ -240,3 +240,84 b' Test rebase across repeating renames:'
    1 files changed, 1 insertions(+), 0 deletions(-)
 
   $ cd ..
+
+Verify that copies get preserved (issue4192).
+  $ hg init copy-gets-preserved
+  $ cd copy-gets-preserved
+
+  $ echo a > a
+  $ hg add a
+  $ hg commit --message "File a created"
+  $ hg copy a b
+  $ echo b > b
+  $ hg commit --message "File b created as copy of a and modified"
+  $ hg copy b c
+  $ echo c > c
+  $ hg commit --message "File c created as copy of b and modified"
+  $ hg copy c d
+  $ echo d > d
+  $ hg commit --message "File d created as copy of c and modified"
+
+Note that there are four entries in the log for d
+  $ hg tglog --follow d
+  @  3: 'File d created as copy of c and modified'
+  |
+  o  2: 'File c created as copy of b and modified'
+  |
+  o  1: 'File b created as copy of a and modified'
+  |
+  o  0: 'File a created'
+  
+Update back to before we performed copies, and inject an unrelated change.
+  $ hg update 0
+  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
+
+  $ echo unrelated > unrelated
+  $ hg add unrelated
+  $ hg commit --message "Unrelated file created"
+  created new head
+  $ hg update 4
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
+Rebase the copies on top of the unrelated change.
+  $ hg rebase --source 1 --dest 4
+  saved backup bundle to $TESTTMP/copy-gets-preserved/.hg/*.hg (glob)
+  $ hg update 4
+  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
+There should still be four entries in the log for d
+  $ hg tglog --follow d
+  @  4: 'File d created as copy of c and modified'
+  |
+  o  3: 'File c created as copy of b and modified'
+  |
+  o  2: 'File b created as copy of a and modified'
+  |
+  o  0: 'File a created'
+  
+Same steps as above, but with --collapse on rebase to make sure the
+copy records collapse correctly.
+  $ hg co 1
+  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
+  $ echo more >> unrelated
+  $ hg ci -m 'unrelated commit is unrelated'
+  created new head
+  $ hg rebase -s 2 --dest 5 --collapse
+  merging b and c to c
+  merging c and d to d
+  saved backup bundle to $TESTTMP/copy-gets-preserved/.hg/*.hg (glob)
+  $ hg co tip
+  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
+This should show both revision 3 and 0 since 'd' was transitively a
+copy of 'a'.
+
+  $ hg tglog --follow d
+  @  3: 'Collapsed revision
+  |  * File b created as copy of a and modified
+  |  * File c created as copy of b and modified
+  |  * File d created as copy of c and modified'
+  o  0: 'File a created'
+  
+
+  $ cd ..