diff mercurial/cmdutil.py @ 28601:cd10171d6c71

graphmod: allow edges to end early

Rather than draw an edge all the way to the bottom of the graph, make it
possible to end an edge to parents that are not part of the graph early on.
This results in a far cleaner graph.

Any edge type can be set to end early; set the ui.graphstyle.<edgetype>
parameter to the empty string to enable this.

For example, setting the following configuration:

    [ui]
    graphstyle.grandparent = :
    graphstyle.missing =

would result in a graph like this:

  o    changeset:   32:d06dffa21a31
  |\   parent:      27:886ed638191b
  | :  parent:      31:621d83e11f67
  | :
  o :  changeset:   31:621d83e11f67
  |\:  parent:      21:d42a756af44d
  | :  parent:      30:6e11cd4b648f
  | :
  o :    changeset:   30:6e11cd4b648f
  |\ \   parent:      28:44ecd0b9ae99
  | ~ :  parent:      29:cd9bb2be7593
  |  /
  o :    changeset:   28:44ecd0b9ae99
  |\ \   parent:      1:6db2ef61d156
  | ~ :  parent:      26:7f25b6c2f0b9
  |  /
  o :    changeset:   26:7f25b6c2f0b9
  |\ \   parent:      18:1aa84d96232a
  | | :  parent:      25:91da8ed57247
  | | :
  | o :  changeset:   25:91da8ed57247
  | |\:  parent:      21:d42a756af44d
  | | :  parent:      24:a9c19a3d96b7
  | | :
  | o :    changeset:   24:a9c19a3d96b7
  | |\ \   parent:      0:e6eb3150255d
  | | ~ :  parent:      23:a01cddf0766d
  | |  /
  | o :    changeset:   23:a01cddf0766d
  | |\ \   parent:      1:6db2ef61d156
  | | ~ :  parent:      22:e0d9cccacb5d
  | |  /
  | o :  changeset:   22:e0d9cccacb5d
  |/:/   parent:      18:1aa84d96232a
  | :    parent:      21:d42a756af44d
  | :
  | o    changeset:   21:d42a756af44d
  | |\   parent:      19:31ddc2c1573b
  | | |  parent:      20:d30ed6450e32
  | | |
  +---o  changeset:   20:d30ed6450e32
  | | |  parent:      0:e6eb3150255d
  | | ~  parent:      18:1aa84d96232a
  | |
  | o    changeset:   19:31ddc2c1573b
  | |\   parent:      15:1dda3f72782d
  | ~ ~  parent:      17:44765d7c06e0
  |
  o  changeset:   18:1aa84d96232a
     parent:      1:6db2ef61d156
     parent:      15:1dda3f72782d

The default configuration leaves all 3 types set to |.

This is part of the work towards moving smartlog upstream; currently smartlog
injects extra nodes into the graph to indicate grandparent relationships (nodes
elided).

--- a/mercurial/cmdutil.py	Sat Mar 19 16:46:15 2016 -0700
+++ b/mercurial/cmdutil.py	Sat Mar 19 16:37:47 2016 -0700
@@ -2227,6 +2227,8 @@
     for name, key in edgetypes.items():
         # experimental config: ui.graphstyle.*
         styles[key] = ui.config('ui', 'graphstyle.%s' % name, styles[key])
+        if not styles[key]:
+            styles[key] = None
     for rev, type, ctx, parents in dag:
         char = formatnode(repo, ctx)
         copies = None