# HG changeset patch
# User Boris Feld <boris.feld@octobus.net>
# Date 1508072463 -7200
# Node ID dbf868623daf6faaf106b19f5f80110aef63be80
# Parent  3340d46a5c3f1ac61d133369df0ecc725a1a5267
bookmark: add a 'check:bookmarks' bundle2 part

This part checks that bookmarks are still at the node they are expected to be.
This allows a pushing client to detect push race where the repository was
updated between the time it discovered the server state and the time it managed
to finish its push.

Such checking already exists when pushing bookmark through pushkey. This new
part can be inserted at the beginning of the bundle, triggering abort earlier.
In addition, we would like to move away from pushey to push bookmark. A step
useful to solve issue5165.

diff -r 3340d46a5c3f -r dbf868623daf mercurial/bundle2.py
--- a/mercurial/bundle2.py	Sun Oct 15 14:59:55 2017 +0200
+++ b/mercurial/bundle2.py	Sun Oct 15 15:01:03 2017 +0200
@@ -156,6 +156,7 @@
 
 from .i18n import _
 from . import (
+    bookmarks,
     changegroup,
     error,
     node as nodemod,
@@ -1787,6 +1788,34 @@
     replyto = int(inpart.params['in-reply-to'])
     op.records.add('changegroup', {'return': ret}, replyto)
 
+@parthandler('check:bookmarks')
+def handlecheckbookmarks(op, inpart):
+    """check location of bookmarks
+
+    This part is to be used to detect push race regarding bookmark, it
+    contains binary encoded (bookmark, node) tuple. If the local state does
+    not marks the one in the part, a PushRaced exception is raised
+    """
+    bookdata = bookmarks.binarydecode(inpart)
+
+    msgstandard = ('repository changed while pushing - please try again '
+                   '(bookmark "%s" move from %s to %s)')
+    msgmissing = ('repository changed while pushing - please try again '
+                  '(bookmark "%s" is missing, expected %s)')
+    msgexist = ('repository changed while pushing - please try again '
+                '(bookmark "%s" set on %s, expected missing)')
+    for book, node in bookdata:
+        currentnode = op.repo._bookmarks.get(book)
+        if currentnode != node:
+            if node is None:
+                finalmsg = msgexist % (book, nodemod.short(currentnode))
+            elif currentnode is None:
+                finalmsg = msgmissing % (book, nodemod.short(node))
+            else:
+                finalmsg = msgstandard % (book, nodemod.short(node),
+                                          nodemod.short(currentnode))
+            raise error.PushRaced(finalmsg)
+
 @parthandler('check:heads')
 def handlecheckheads(op, inpart):
     """check that head of the repo did not change