[PATCH] rebase: allow rebase to ancestor (issue3010)

[pierre-yves.david at logilab.fr]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at logilab.fr>
# Date 1316444233 -7200
# Node ID 27d784f66d741ff8e12fc55fa0080862b67d9203
# Parent  2ca855126091fb099f3534e32258e9f04e9e7169
rebase: allow rebase to ancestor (issue3010)

We only deny rebasing onto direct parent. Thanks to the ancestor argument of
merge. the "implementation" of this feature only consist in loosing the check
and imply detach when rebasing on ancestor.

diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -534,15 +534,18 @@ def buildstate(repo, dest, src, base, de
                             [s.node for s in repo.mq.applied]):
         raise util.Abort(_('cannot rebase onto an applied mq patch'))
 
     if src:
         commonbase = repo[src].ancestor(repo[dest])
-        samebranch = repo[src].branch() == repo[dest].branch()
         if commonbase == repo[src]:
             raise util.Abort(_('source is ancestor of destination'))
-        if samebranch and commonbase == repo[dest]:
-            raise util.Abort(_('source is descendant of destination'))
+        if commonbase == repo[dest]:
+            samebranch = repo[src].branch() == repo[dest].branch()
+            if samebranch and repo[src] in repo[dest].children():
+                raise util.Abort(_('source is children of destination'))
+            # rebase on ancestor, force detach
+            detach = True
         source = repo[src].rev()
         if detach:
             # We need to keep track of source's ancestors up to the common base
             srcancestors = set(repo.changelog.ancestors(source))
             baseancestors = set(repo.changelog.ancestors(commonbase.rev()))
diff --git a/tests/test-rebase-detach.t b/tests/test-rebase-detach.t
--- a/tests/test-rebase-detach.t
+++ b/tests/test-rebase-detach.t
@@ -279,5 +279,27 @@ Rebasing across null as ancestor
   | |
   | o  1: 'E'
   |/
   o  0: 'A'
   
+
+  $ hg rebase -d 5 -s 7
+  saved backup bundle to $TESTTMP/a5/.hg/strip-backup/13547172c9c0-backup.hg
+  $ hg tglog
+  @  8: 'D'
+  |
+  o  7: 'C'
+  |
+  | o  6: 'B'
+  |/
+  o  5: 'extra branch'
+  
+  o  4: 'H'
+  |
+  | o  3: 'G'
+  |/|
+  o |  2: 'F'
+  | |
+  | o  1: 'E'
+  |/
+  o  0: 'A'
+  
diff --git a/tests/test-rebase-parameters.t b/tests/test-rebase-parameters.t
--- a/tests/test-rebase-parameters.t
+++ b/tests/test-rebase-parameters.t
@@ -49,11 +49,11 @@ These fail:
 
   $ hg clone -q -u . a a1
   $ cd a1
 
   $ hg rebase -s 8 -d 7
-  abort: source is descendant of destination
+  abort: source is children of destination
   [255]
 
   $ hg rebase --continue --abort
   abort: cannot use both abort and continue
   [255]
diff --git a/tests/test-rebase-scenario-global.t b/tests/test-rebase-scenario-global.t
--- a/tests/test-rebase-scenario-global.t
+++ b/tests/test-rebase-scenario-global.t
@@ -210,11 +210,11 @@ G onto F - rebase onto an ancestor:
 
   $ hg clone -q -u . a a7
   $ cd a7
 
   $ hg rebase -s 6 -d 5
-  abort: source is descendant of destination
+  abort: source is children of destination
   [255]
 
 F onto G - rebase onto a descendant:
 
   $ hg rebase -s 5 -d 6
@@ -246,5 +246,27 @@ F onto G - rebase onto a descendant:
 
   $ hg rebase -b 5 -d 6
   nothing to rebase
   [1]
 
+C onto A - rebase onto a ancestor:
+
+  $ hg rebase -d 0 -s 2
+  saved backup bundle to $TESTTMP/a7/.hg/strip-backup/5fddd98957c8-backup.hg
+  $ hg tglog
+  @  7: 'D'
+  |
+  o  6: 'C'
+  |
+  | o  5: 'H'
+  | |
+  | | o  4: 'G'
+  | |/|
+  | o |  3: 'F'
+  |/ /
+  | o  2: 'E'
+  |/
+  | o  1: 'B'
+  |/
+  o  0: 'A'
+  
+