Merge branch 'jc/signed-commit' and 'jc/pull-signed-tag'

They both use the extended headers in commit objects, and the former has
necessary infrastructure to show them that is useful to view the result of
the latter.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --combined builtin/commit.c
index 0c64c880d5fe7106e391e677f6a32dd46e73b36b,7e8a1cf4e074053a78f2f029e8c03f17c9053bf0..fa41ec8c878a6af63e17b79996148be85dcfccef
--- 1/builtin/commit.c
--- 2/builtin/commit.c
+++ b/builtin/commit.c
@@@ -26,6 -26,7 +26,7 @@@
  #include "unpack-trees.h"
  #include "quote.h"
  #include "submodule.h"
+ #include "gpg-interface.h"
  
  static const char * const builtin_commit_usage[] = {
        "git commit [options] [--] <filepattern>...",
@@@ -85,6 -86,8 +86,8 @@@ static int all, edit_flag, also, intera
  static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
  static int no_post_rewrite, allow_empty_message;
  static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
+ static char *sign_commit;
+ 
  /*
   * The default commit message cleanup mode will remove the lines
   * beginning with # (shell comments) and leading and trailing
@@@ -144,6 -147,8 +147,8 @@@ static struct option builtin_commit_opt
        OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
        OPT_STRING(0, "cleanup", &cleanup_arg, "default", "how to strip spaces and #comments from message"),
        OPT_BOOLEAN(0, "status", &include_status, "include status in commit message template"),
+       { OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id",
+         "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
        /* end commit message options */
  
        OPT_GROUP("Commit contents options"),
@@@ -1324,6 -1329,7 +1329,7 @@@ static void print_summary(const char *p
  static int git_commit_config(const char *k, const char *v, void *cb)
  {
        struct wt_status *s = cb;
+       int status;
  
        if (!strcmp(k, "commit.template"))
                return git_config_pathname(&template_file, k, v);
@@@ -1332,6 -1338,9 +1338,9 @@@
                return 0;
        }
  
+       status = git_gpg_config(k, v, NULL);
+       if (status)
+               return status;
        return git_status_config(k, v, s);
  }
  
@@@ -1484,15 -1493,11 +1493,15 @@@ int cmd_commit(int argc, const char **a
                exit(1);
        }
  
 -      if (amend)
 +      if (amend) {
                extra = read_commit_extra_headers(current_head);
 +      } else {
 +              struct commit_extra_header **tail = &extra;
 +              append_merge_tag_headers(parents, &tail);
 +      }
  
        if (commit_tree_extended(sb.buf, active_cache_tree->sha1, parents, sha1,
-                                author_ident.buf, extra)) {
+                                author_ident.buf, sign_commit, extra)) {
                rollback_index_files();
                die(_("failed to write commit object"));
        }