Merge branch 'jc/rerere'

* jc/rerere:
  rerere.autoupdate
  t4200: fix rerere test
  rerere: remove dubious "tail_optimization"
  git-rerere: detect unparsable conflicts
  rerere: rerere_created_at() and has_resolution() abstraction

diff --cc Documentation/config.txt
index a403d46c1ba3068abe5c0583533de651f6116fd4,0c7cf618ed2847d56d811e39c67ea53bdd71796b..838794dca71d59f82eaec770ba31537297af8066
--- 1/Documentation/config.txt
--- 2/Documentation/config.txt
+++ b/Documentation/config.txt
@@@ -655,9 -647,14 +655,14 @@@ gc.rerereresolved:
  
  gc.rerereunresolved::
        Records of conflicted merge you have not resolved are
 -      kept for this many days when `git rerere gc` is run.
 +      kept for this many days when 'git-rerere gc' is run.
        The default is 15 days.  See linkgit:git-rerere[1].
  
+ rerere.autoupdate::
+       When set to true, `git-rerere` updates the index with the
+       resulting contents after it cleanly resolves conflicts using
+       previously recorded resolution.  Defaults to false.
+ 
  rerere.enabled::
        Activate recording of resolved conflicts, so that identical
        conflict hunks can be resolved automatically, should they