diff mercurial/cmdutil.py @ 45771:f90a5c211251

rebase: change and standarize template for rebase's one-line summary

This removes the default template in rebase and switches to a
centrally defined template. I've simplified it a bit to avoid the
conditional parenthesis. I've also added labels so the different parts
can be easily colored. The template is somewhat similar to what we've
used internally at Google for a few years.

I'm happy to change the template if others have opinions. Should we
reuse the `color.log.` names as I have?

Differential Revision: https://phab.mercurial-scm.org/D9252

--- a/mercurial/cmdutil.py	Thu Oct 22 23:10:06 2020 -0700
+++ b/mercurial/cmdutil.py	Tue Oct 27 15:33:15 2020 -0700
@@ -1222,8 +1222,16 @@
     if not spec:
         spec = default_spec
     if not spec:
-        # TODO: Pick a default we can agree on. This isn't used yet.
-        raise error.ProgrammingError(b"no default one-line summary defined yet")
+        spec = (
+            b'{separate(" ", '
+            b'label("log.changeset", "{rev}:{node|short}")'
+            b', '
+            b'label("log.tag", tags)'
+            b', '
+            b'label("log.bookmark", bookmarks)'
+            b')} '
+            b'"{label("log.desc", desc|firstline)}"'
+        )
     text = rendertemplate(ctx, spec)
     return text.split(b'\n')[0]