Merge branch 'jc/diff-mark'

* jc/diff-mark:
diff: honor binariness specified in attributes
Fix configuration syntax to specify customized hunk header patterns.
Per-path attribute based hunk header selection.
Future-proof source for changes in xdemitconf_t
Introduce diff_filespec_is_binary()

diff --combined builtin-rerere.c
index 3196151cc4be4b6fdf6e19735ef26471fc68940f,01f3848f1429cca93a5953118a74276f7f66b065..c25b3d5586ff08061295350b5ceae01246931037
--- 1/builtin-rerere.c
--- 2/builtin-rerere.c
+++ b/builtin-rerere.c
@@@ -12,9 -12,6 +12,9 @@@ static const char git_rerere_usage[] 
  static int cutoff_noresolve = 15;
  static int cutoff_resolve = 60;
  
 +/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
 +static int rerere_enabled = -1;
 +
  static char *merge_rr_path;
  
  static const char *rr_path(const char *name, const char *file)
@@@ -285,8 -282,8 +285,8 @@@ static int diff_two(const char *file1, 
        printf("--- a/%s\n+++ b/%s\n", label1, label2);
        fflush(stdout);
        xpp.flags = XDF_NEED_MINIMAL;
+       memset(&xecfg, 0, sizeof(xecfg));
        xecfg.ctxlen = 3;
-       xecfg.flags = 0;
        ecb.outf = outf;
        xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
  
@@@ -390,41 -387,21 +390,41 @@@ static int git_rerere_config(const cha
                cutoff_resolve = git_config_int(var, value);
        else if (!strcmp(var, "gc.rerereunresolved"))
                cutoff_noresolve = git_config_int(var, value);
 +      else if (!strcmp(var, "rerere.enabled"))
 +              rerere_enabled = git_config_bool(var, value);
        else
                return git_default_config(var, value);
        return 0;
  }
  
 -int cmd_rerere(int argc, const char **argv, const char *prefix)
 +static int is_rerere_enabled(void)
  {
 -      struct path_list merge_rr = { NULL, 0, 0, 1 };
 -      int i, fd = -1;
        struct stat st;
 +      const char *rr_cache;
 +      int rr_cache_exists;
  
 -      if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
 +      if (!rerere_enabled)
                return 0;
  
 +      rr_cache = git_path("rr-cache");
 +      rr_cache_exists = !stat(rr_cache, &st) && S_ISDIR(st.st_mode);
 +      if (rerere_enabled < 0)
 +              return rr_cache_exists;
 +
 +      if (!rr_cache_exists &&
 +          (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
 +              die("Could not create directory %s", rr_cache);
 +      return 1;
 +}
 +
 +int cmd_rerere(int argc, const char **argv, const char *prefix)
 +{
 +      struct path_list merge_rr = { NULL, 0, 0, 1 };
 +      int i, fd = -1;
 +
        git_config(git_rerere_config);
 +      if (!is_rerere_enabled())
 +              return 0;
  
        merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
        fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
@@@ -434,7 -411,6 +434,7 @@@
                return do_plain_rerere(&merge_rr, fd);
        else if (!strcmp(argv[1], "clear")) {
                for (i = 0; i < merge_rr.nr; i++) {
 +                      struct stat st;
                        const char *name = (const char *)merge_rr.items[i].util;
                        if (!stat(git_path("rr-cache/%s", name), &st) &&
                                        S_ISDIR(st.st_mode) &&