Merge branch 'mh/packed-refs-various'

Update reading and updating packed-refs file, correcting corner case
bugs.

* mh/packed-refs-various: (33 commits)
  refs: handle the main ref_cache specially
  refs: change do_for_each_*() functions to take ref_cache arguments
  pack_one_ref(): do some cheap tests before a more expensive one
  pack_one_ref(): use write_packed_entry() to do the writing
  pack_one_ref(): use function peel_entry()
  refs: inline function do_not_prune()
  pack_refs(): change to use do_for_each_entry()
  refs: use same lock_file object for both ref-packing functions
  pack_one_ref(): rename "path" parameter to "refname"
  pack-refs: merge code from pack-refs.{c,h} into refs.{c,h}
  pack-refs: rename handle_one_ref() to pack_one_ref()
  refs: extract a function write_packed_entry()
  repack_without_ref(): write peeled refs in the rewritten file
  t3211: demonstrate loss of peeled refs if a packed ref is deleted
  refs: change how packed refs are deleted
  search_ref_dir(): return an index rather than a pointer
  repack_without_ref(): silence errors for dangling packed refs
  t3210: test for spurious error messages for dangling packed refs
  refs: change the internal reference-iteration API
  refs: extract a function peel_entry()
  ...

Makefile

@@ -685,7 +685,6 @@ LIB_H += notes-cache.h
 LIB_H += notes-merge.h
 LIB_H += notes.h
 LIB_H += object.h
-LIB_H += pack-refs.h
 LIB_H += pack-revindex.h
 LIB_H += pack.h
 LIB_H += parse-options.h
@@ -818,7 +817,6 @@ LIB_OBJS += notes-cache.o
 LIB_OBJS += notes-merge.o
 LIB_OBJS += object.o
 LIB_OBJS += pack-check.o
-LIB_OBJS += pack-refs.o
 LIB_OBJS += pack-revindex.o
 LIB_OBJS += pack-write.o
 LIB_OBJS += pager.o

builtin/clone.c

@@ -18,7 +18,6 @@
 #include "transport.h"
 #include "strbuf.h"
 #include "dir.h"
-#include "pack-refs.h"
 #include "sigchain.h"
 #include "branch.h"
 #include "remote.h"

builtin/pack-refs.c

@@ -1,6 +1,6 @@
 #include "builtin.h"
 #include "parse-options.h"
-#include "pack-refs.h"
+#include "refs.h"
 
 static char const * const pack_refs_usage[] = {
 	N_("git pack-refs [options]"),