destupdate: move obsolete handling first

This block was overwriting any result from the previous block anyway. So we move
it first to prove it is possible and we'll extract it in its own function in the
next patch.

mercurial/destutil.py

@@ -53,22 +53,8 b' def destupdate(repo, clean=False, check='
     node = None
     wc = repo[None]
     p1 = wc.p1()
-    movemark, activemark = None
-
-    if node is None:
-        # we also move the active bookmark, if any
-        node, movemark = bookmarks.calculateupdate(repo.ui, repo, None)
-        if node is not None:
-            activemark = node
+    movemark = activemark = None
 
-        if node is None:
-            try:
-                node = repo.branchtip(wc.branch())
-            except error.RepoLookupError:
-                if wc.branch() == 'default': # no default branch!
-                    node = repo.lookup('tip') # update to tip
-                else:
-                    raise error.Abort(_("branch %s not found") % wc.branch())
     if p1.obsolete() and not p1.children():
         # allow updating to successors
         successors = obsolete.successorssets(repo, p1.node())
@@ -94,6 +80,23 b' def destupdate(repo, clean=False, check='
             # get the max revision for the given successors set,
             # i.e. the 'tip' of a set
             node = repo.revs('max(%ln)', successors).first()
+            if bookmarks.isactivewdirparent(repo):
+                movemark = repo['.'].node()
+
+    if node is None:
+        # we also move the active bookmark, if any
+        node, movemark = bookmarks.calculateupdate(repo.ui, repo, None)
+        if node is not None:
+            activemark = node
+
+        if node is None:
+            try:
+                node = repo.branchtip(wc.branch())
+            except error.RepoLookupError:
+                if wc.branch() == 'default': # no default branch!
+                    node = repo.lookup('tip') # update to tip
+                else:
+                    raise error.Abort(_("branch %s not found") % wc.branch())
     rev = repo[node].rev()
 
     _destupdatevalidate(repo, rev, clean, check)