[PATCH] strip: factor out revset calculation for strip -B

[Ryan McElroy]

# HG changeset patch
# User Ryan McElroy <rmcelroy at fb.com>
# Date 1444427339 25200
#      Fri Oct 09 14:48:59 2015 -0700
# Node ID 34e4ead82b70ffeb4458ae38aa3ad749026378c3
# Parent  b80b2ee71a08d00ec4008f3131bdf3c72e4ec2ba
strip: factor out revset calculation for strip -B

This will allow reusing it in evolve and overriding it in other extensions.

diff --git a/hgext/strip.py b/hgext/strip.py
--- a/hgext/strip.py
+++ b/hgext/strip.py
@@ -72,6 +72,12 @@ def strip(ui, repo, revs, update=True, b
     finally:
         release(lock, wlock)
 
+def stripbmrevset(repo, mark):
+    """The revset to strip when called with -B mark"""
+    return repo.revs("ancestors(bookmark(%s)) - "
+                     "ancestors(head() and not bookmark(%s)) - "
+                     "ancestors(bookmark() and not bookmark(%s))",
+                     mark, mark, mark)
 
 @command("strip",
          [
@@ -142,10 +148,7 @@ def stripcmd(ui, repo, *revs, **opts):
                     uniquebm = False
                     break
             if uniquebm:
-                rsrevs = repo.revs("ancestors(bookmark(%s)) - "
-                                   "ancestors(head() and not bookmark(%s)) - "
-                                   "ancestors(bookmark() and not bookmark(%s))",
-                                   mark, mark, mark)
+                rsrevs = stripbmrevset(repo, mark)
                 revs.update(set(rsrevs))
             if not revs:
                 del marks[mark]