<2> Rewind the master branch to get rid of those three commits.
<3> Switch to "topic/wip" branch and keep working.
-Undo update-index::
+Undo add::
+
------------
$ edit <1>
-$ git-update-index frotz.c filfre.c
+$ git add frotz.c filfre.c
$ mailx <2>
$ git reset <3>
$ git pull git://info.example.com/ nitfol <4>
+
------------
$ git pull <1>
-Trying really trivial in-index merge...
-fatal: Merge requires file-level merging
-Nope.
-...
Auto-merging nitfol
CONFLICT (content): Merge conflict in nitfol
Automatic merge failed/prevented; fix up by hand