Merge branch 'rs/unpack-trees-plug-leak'

* rs/unpack-trees-plug-leak:
unpack-trees: free cache_entry array members for merges
diff-lib, read-tree, unpack-trees: mark cache_entry array paramters const
diff-lib, read-tree, unpack-trees: mark cache_entry pointers const
unpack-trees: create working copy of merge entry in merged_entry
unpack-trees: factor out dup_entry
read-cache: mark cache_entry pointers const
cache: mark cache_entry pointers const

diff --combined cache.h
index df532f8e4a597a0c9c4d3cbb4980f5d62a106334,01e8760ecff19d1ae0ef3bb2d0989bc3c74e789d..820aa05c7a6f42aa3a3599c48f560a1074132596
--- 1/cache.h
--- 2/cache.h
+++ b/cache.h
@@@ -190,7 -190,8 +190,8 @@@ struct cache_entry 
   * another. But we never change the name, or the hash state!
   */
  #define CE_STATE_MASK (CE_HASHED | CE_UNHASHED)
- static inline void copy_cache_entry(struct cache_entry *dst, struct cache_entry *src)
+ static inline void copy_cache_entry(struct cache_entry *dst,
+                                   const struct cache_entry *src)
  {
        unsigned int state = dst->ce_flags & CE_STATE_MASK;
  
@@@ -222,7 -223,8 +223,8 @@@ static inline unsigned int create_ce_mo
                return S_IFGITLINK;
        return S_IFREG | ce_permissions(mode);
  }
- static inline unsigned int ce_mode_from_stat(struct cache_entry *ce, unsigned int mode)
+ static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
+                                            unsigned int mode)
  {
        extern int trust_executable_bit, has_symlinks;
        if (!has_symlinks && S_ISREG(mode) &&
@@@ -480,8 -482,8 +482,8 @@@ extern void *read_blob_data_from_index(
  #define CE_MATCH_RACY_IS_DIRTY                02
  /* do stat comparison even if CE_SKIP_WORKTREE is true */
  #define CE_MATCH_IGNORE_SKIP_WORKTREE 04
- extern int ie_match_stat(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
- extern int ie_modified(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
+ extern int ie_match_stat(const struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
+ extern int ie_modified(const struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
  
  #define PATHSPEC_ONESTAR 1    /* the pathspec pattern sastisfies GFNM_ONESTAR */
  
@@@ -910,7 -912,6 +912,7 @@@ void show_date_relative(unsigned long t
                        struct strbuf *timebuf);
  int parse_date(const char *date, char *buf, int bufsize);
  int parse_date_basic(const char *date, unsigned long *timestamp, int *offset);
 +int parse_expiry_date(const char *date, unsigned long *timestamp);
  void datestamp(char *buf, int bufsize);
  #define approxidate(s) approxidate_careful((s), NULL)
  unsigned long approxidate_careful(const char *, int *);
@@@ -1025,21 -1026,9 +1027,21 @@@ struct ref 
        unsigned int
                force:1,
                forced_update:1,
 -              merge:1,
                deletion:1,
                matched:1;
 +
 +      /*
 +       * Order is important here, as we write to FETCH_HEAD
 +       * in numeric order. And the default NOT_FOR_MERGE
 +       * should be 0, so that xcalloc'd structures get it
 +       * by default.
 +       */
 +      enum {
 +              FETCH_HEAD_MERGE = -1,
 +              FETCH_HEAD_NOT_FOR_MERGE = 0,
 +              FETCH_HEAD_IGNORE = 1
 +      } fetch_head_status;
 +
        enum {
                REF_STATUS_NONE = 0,
                REF_STATUS_OK,