# HG changeset patch
# User Steve Losh <steve@stevelosh.com>
# Date 1254344772 14400
# Node ID 8e444c0f0dd9931eb23cd105de30b12aa3508d24
# Parent  b60fac62931ea98c2967276f5316331c4d54b396
Make {rev} behave correctly for some corner cases.

The {rev} keyword now expands like so:

    * To nothing, when the working directory has no parent (i.e. when
      in a freshly init'ed repo or after running 'hg update null').
    * To the revision number of the (first) parent of the working
      directory otherwise.

fixes issue 9

diff -r b60fac62931e -r 8e444c0f0dd9 prompt.py
--- a/prompt.py	Sun Sep 27 10:30:14 2009 -0400
+++ b/prompt.py	Wed Sep 30 17:06:12 2009 -0400
@@ -178,11 +178,11 @@
         out_g = (g[0],) + (g[-1],)
         
         parents = repo[None].parents()
-        p = 0 if '|merge' not in g else 1
-        p = p if len(parents) > p else None
+        parent = 0 if '|merge' not in g else 1
+        parent = parent if len(parents) > parent else None
         
-        rev = parents[p].rev() if p is not None else None
-        return _with_groups(out_g, str(rev)) if rev else ''
+        rev = parents[parent].rev() if parent is not None else -1
+        return _with_groups(out_g, str(rev)) if rev >= 0 else ''
     
     def _node(m):
         g = m.groups()