Merge branch 'rs/sha1-name-readdir-optim'

Optimize "what are the object names already taken in an alternate
object database?" query that is used to derive the length of prefix
an object name is uniquely abbreviated to.

* rs/sha1-name-readdir-optim:
sha1_file: guard against invalid loose subdirectory numbers
sha1_file: let for_each_file_in_obj_subdir() handle subdir names
p4205: add perf test script for pretty log formats
sha1_name: cache readdir(3) results in find_short_object_filename()

diff --cc builtin/fsck.c
Simple merge

diff --cc builtin/prune.c
Simple merge

diff --cc cache.h
index c958fc3ce552daf0ff10a8566b0fdda5b347d0b8,7f7ec5d56d8244d42ebe824b1bbc960ddf87634e..c12f45289044dd846a1ddbfecf24ea84d71ef29f
--- 1/cache.h
--- 2/cache.h
+++ b/cache.h
@@@ -11,7 -11,7 +11,8 @@@
  #include "string-list.h"
  #include "pack-revindex.h"
  #include "hash.h"
 +#include "path.h"
+ #include "sha1-array.h"
  
  #ifndef platform_SHA_CTX
  /*

diff --cc sha1_file.c
Simple merge

diff --cc sha1_name.c
Simple merge