bookmarks: pull --update updates to active bookmark if it moved (issue4007)

This makes `hg pull --update` behave the same wrt the active bookmark as
`hg pull && hg update` does as of 2096e025a728. A helper function,
bookmarks.calculateupdate, is added to prevent code duplication between
postincoming and update.

mercurial/bookmarks.py

@@ -170,6 +170,19 b' def deletedivergent(repo, deletefrom, bm'
                 deleted = True
     return deleted
 
+def calculateupdate(ui, repo, checkout):
+    '''Return a tuple (targetrev, movemarkfrom) indicating the rev to
+    check out and where to move the active bookmark from, if needed.'''
+    movemarkfrom = None
+    if checkout is None:
+        curmark = repo._bookmarkcurrent
+        if iscurrent(repo):
+            movemarkfrom = repo['.'].node()
+        elif curmark:
+            ui.status(_("updating to active bookmark %s\n") % curmark)
+            checkout = curmark
+    return (checkout, movemarkfrom)
+
 def update(repo, parents, node):
     deletefrom = parents
     marks = repo._bookmarks

mercurial/commands.py

@@ -4520,7 +4520,7 b' def postincoming(ui, repo, modheads, opt'
     if modheads == 0:
         return
     if optupdate:
-        movemarkfrom = repo['.'].node()
+        checkout, movemarkfrom = bookmarks.calculateupdate(ui, repo, checkout)
         try:
             ret = hg.update(repo, checkout)
         except util.Abort, inst:
@@ -5829,14 +5829,7 b' def update(ui, repo, node=None, rev=None'
     cmdutil.clearunfinished(repo)
 
     # with no argument, we also move the current bookmark, if any
-    movemarkfrom = None
-    if rev is None:
-        curmark = repo._bookmarkcurrent
-        if bookmarks.iscurrent(repo):
-            movemarkfrom = repo['.'].node()
-        elif curmark:
-            ui.status(_("updating to active bookmark %s\n") % curmark)
-            rev = curmark
+    rev, movemarkfrom = bookmarks.calculateupdate(ui, repo, rev)
 
     # if we defined a bookmark, we have to remember the original bookmark name
     brev = rev

tests/test-bookmarks.t

@@ -507,19 +507,37 b" update to current bookmark if it's not t"
    * Z                         3:125c9a1d6df6
      x  y                      2:db815d6d32e6
 
+pull --update works the same as pull && update
+
+  $ hg bookmark -r3 Y
+  moving bookmark 'Y' forward from db815d6d32e6
+  $ hg -R cloned-bookmarks-update update Y
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg -R cloned-bookmarks-update pull --update .
+  pulling from .
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 2 changesets with 2 changes to 2 files (+1 heads)
+  updating bookmark Y
+  updating bookmark Z
+  updating to active bookmark Y
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
 test wrongly formated bookmark
 
   $ echo '' >> .hg/bookmarks
   $ hg bookmarks
      X2                        1:925d80f479bb
-     Y                         2:db815d6d32e6
+     Y                         3:125c9a1d6df6
    * Z                         3:125c9a1d6df6
      x  y                      2:db815d6d32e6
   $ echo "Ican'thasformatedlines" >> .hg/bookmarks
   $ hg bookmarks
   malformed line in .hg/bookmarks: "Ican'thasformatedlines"
      X2                        1:925d80f479bb
-     Y                         2:db815d6d32e6
+     Y                         3:125c9a1d6df6
    * Z                         3:125c9a1d6df6
      x  y                      2:db815d6d32e6