[PATCH 09 of 15 V5] bookmarks: prevent divergent bookmark from being updated unexpectedly

[FUJIWARA Katsunori]

# HG changeset patch
# User FUJIWARA Katsunori <foozy at lares.dti.ne.jp>
# Date 1383882352 -32400
#      Fri Nov 08 12:45:52 2013 +0900
# Node ID c78c40d11ff9c6cfa32bd6aed4fe781a613255b4
# Parent  678478b86dd994059e2c9446863aca80a3867fe5
bookmarks: prevent divergent bookmark from being updated unexpectedly

Before this patch, "@99" suffixed bookmark may be updated unexpectedly
by the bookmark value on the remote side at "hg pull", if all of "@1"
to "@99" suffixed bookmarks exist in the local repository, because
variable "n" still refers "@99" suffixed bookmark after the loop to
examine "@num" suffixes, even though it already exists in the local
repository.

This patch prevents divergent bookmark from being updated
unexpectedly, and shows warning message in such situation.

This patch uses original python script "seq.py" instead of "seq"
command to create sequence numbers in the test, because "seq" command
may not be available: it isn't defined in recent POSIX specification
(POSIX.1-2001 2013 Edition or XPG7)

diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py
--- a/mercurial/bookmarks.py
+++ b/mercurial/bookmarks.py
@@ -333,6 +333,8 @@
         n = '%s@%d' % (b, x)
         if n not in localmarks:
             break
+    else:
+        n = None
     # try to use an @pathalias suffix
     # if an @pathalias already exists, we overwrite (update) it
     for p, u in ui.configitems("paths"):
@@ -356,8 +358,13 @@
                         _("updating bookmark %s\n") % (b)))
     for b, scid, dcid in diverge:
         db = _diverge(ui, b, path, localmarks)
-        changed.append((db, bin(scid), ui.warn,
-                        _("divergent bookmark %s stored as %s\n") % (b, db)))
+        if db:
+            changed.append((db, bin(scid), ui.warn,
+                            _("divergent bookmark %s stored as %s\n") %
+                            (b, db)))
+        else:
+            ui.warn(_("warning: fail to assign new divergent bookmark to %s\n")
+                    % (b))
     if changed:
         for b, node, writer, msg in sorted(changed):
             localmarks[b] = node
diff --git a/tests/test-bookmarks-pushpull.t b/tests/test-bookmarks-pushpull.t
--- a/tests/test-bookmarks-pushpull.t
+++ b/tests/test-bookmarks-pushpull.t
@@ -158,6 +158,23 @@
      Z                         2:0d2164f0ce0d
      foo                       -1:000000000000
    * foobar                    1:9b140be10808
+  $ cat > $TESTTMP/seq.py <<EOF
+  > import sys
+  > for i in xrange(*[int(a) for a in sys.argv[1:]]):
+  >     print i
+  > EOF
+  $ python $TESTTMP/seq.py 1 100 | while read i; do hg bookmarks -r 000000000000 "X@${i}"; done
+  $ hg pull ../a
+  pulling from ../a
+  searching for changes
+  no changes found
+  warning: fail to assign new divergent bookmark to X
+  divergent bookmark @ stored as @1
+  $ hg bookmarks | grep '^   X' | grep -v ':000000000000'
+     X                         1:9b140be10808
+     X at foo                     2:0d2164f0ce0d
+  $ python $TESTTMP/seq.py 1 100 | while read i; do hg bookmarks -d "X@${i}"; done
+  $ hg bookmarks -d "@1"
   $ hg push -f ../a
   pushing to ../a
   searching for changes