Merge branch 'jc/deprecate-old-syntax-from-merge'

* jc/deprecate-old-syntax-from-merge:
git-merge: a deprecation notice of the ancient command line syntax

diff --combined builtin-merge.c
index fc7066e3c7053ba697c705f983f8dc7dac19963b,6bf841e78c403600427f00d3e3a545da6f43aa3c..21045776b3199bd9b8af06cf150801d67e5107f1
--- 1/builtin-merge.c
--- 2/builtin-merge.c
+++ b/builtin-merge.c
@@@ -43,7 -43,6 +43,7 @@@ static const char * const builtin_merge
  
  static int show_diffstat = 1, option_log, squash;
  static int option_commit = 1, allow_fast_forward = 1;
 +static int fast_forward_only;
  static int allow_trivial = 1, have_message;
  static struct strbuf merge_msg;
  static struct commit_list *remoteheads;
@@@ -107,8 -106,8 +107,8 @@@ static struct strategy *get_strategy(co
                                        found = 1;
                        if (!found)
                                add_cmdname(&not_strategies, ent->name, ent->len);
 -                      exclude_cmds(&main_cmds, &not_strategies);
                }
 +              exclude_cmds(&main_cmds, &not_strategies);
        }
        if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
                fprintf(stderr, "Could not find merge strategy '%s'.\n", name);
@@@ -167,9 -166,7 +167,9 @@@ static struct option builtin_merge_opti
        OPT_BOOLEAN(0, "commit", &option_commit,
                "perform a commit if the merge succeeds (default)"),
        OPT_BOOLEAN(0, "ff", &allow_fast_forward,
 -              "allow fast forward (default)"),
 +              "allow fast-forward (default)"),
 +      OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
 +              "abort if fast-forward is not possible"),
        OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
                "merge strategy to use", option_parse_strategy),
        OPT_CALLBACK('m', "message", &merge_msg, "message",
@@@ -267,7 -264,6 +267,7 @@@ static void squash_message(void
        struct strbuf out = STRBUF_INIT;
        struct commit_list *j;
        int fd;
 +      struct pretty_print_context ctx = {0};
  
        printf("Squash commit -- not updating HEAD\n");
        fd = open(git_path("SQUASH_MSG"), O_WRONLY | O_CREAT, 0666);
@@@ -289,15 -285,13 +289,15 @@@
        if (prepare_revision_walk(&rev))
                die("revision walk setup failed");
  
 +      ctx.abbrev = rev.abbrev;
 +      ctx.date_mode = rev.date_mode;
 +
        strbuf_addstr(&out, "Squashed commit of the following:\n");
        while ((commit = get_revision(&rev)) != NULL) {
                strbuf_addch(&out, '\n');
                strbuf_addf(&out, "commit %s\n",
                        sha1_to_hex(commit->object.sha1));
 -              pretty_print_commit(rev.commit_format, commit, &out, rev.abbrev,
 -                      NULL, NULL, rev.date_mode, 0);
 +              pretty_print_commit(rev.commit_format, commit, &out, &ctx);
        }
        if (write(fd, out.buf, out.len) < 0)
                die_errno("Writing SQUASH_MSG");
@@@ -656,7 -650,6 +656,7 @@@ static int checkout_fast_forward(unsign
        opts.verbose_update = 1;
        opts.merge = 1;
        opts.fn = twoway_merge;
 +      opts.msgs = get_porcelain_error_msgs();
  
        trees[nr_trees] = parse_tree_indirect(head);
        if (!trees[nr_trees++])
@@@ -796,6 -789,11 +796,11 @@@ static int suggest_conflicts(void
        return 1;
  }
  
+ static const char deprecation_warning[] =
+       "'git merge <msg> HEAD <commit>' is deprecated. Please update\n"
+       "your script to use 'git merge -m <msg> <commit>' instead.\n"
+       "In future versions of git, this syntax will be removed.";
+ 
  static struct commit *is_old_style_invocation(int argc, const char **argv)
  {
        struct commit *second_token = NULL;
@@@ -809,6 -807,7 +814,7 @@@
                        die("'%s' is not a commit", argv[1]);
                if (hashcmp(second_token->object.sha1, head))
                        return NULL;
+               warning(deprecation_warning);
        }
        return second_token;
  }
@@@ -847,6 -846,7 +853,6 @@@ int cmd_merge(int argc, const char **ar
        const char *best_strategy = NULL, *wt_strategy = NULL;
        struct commit_list **remotes = &remoteheads;
  
 -      setup_work_tree();
        if (file_exists(git_path("MERGE_HEAD")))
                die("You have not concluded your merge. (MERGE_HEAD exists)");
        if (read_cache_unmerged())
@@@ -880,9 -880,6 +886,9 @@@
                option_commit = 0;
        }
  
 +      if (!allow_fast_forward && fast_forward_only)
 +              die("You cannot combine --no-ff with --ff-only.");
 +
        if (!argc)
                usage_with_options(builtin_merge_usage,
                        builtin_merge_options);
@@@ -1022,7 -1019,7 +1028,7 @@@
                                hex,
                                find_unique_abbrev(remoteheads->item->object.sha1,
                                DEFAULT_ABBREV));
 -              strbuf_addstr(&msg, "Fast forward");
 +              strbuf_addstr(&msg, "Fast-forward");
                if (have_message)
                        strbuf_addstr(&msg,
                                " (no commit created; -m option ignored)");
@@@ -1040,16 -1037,16 +1046,16 @@@
        } else if (!remoteheads->next && common->next)
                ;
                /*
 -               * We are not doing octopus and not fast forward.  Need
 +               * We are not doing octopus and not fast-forward.  Need
                 * a real merge.
                 */
        else if (!remoteheads->next && !common->next && option_commit) {
                /*
 -               * We are not doing octopus, not fast forward, and have
 +               * We are not doing octopus, not fast-forward, and have
                 * only one common.
                 */
                refresh_cache(REFRESH_QUIET);
 -              if (allow_trivial) {
 +              if (allow_trivial && !fast_forward_only) {
                        /* See if it is really trivial. */
                        git_committer_info(IDENT_ERROR_ON_NO_NAME);
                        printf("Trying really trivial in-index merge...\n");
@@@ -1088,9 -1085,6 +1094,9 @@@
                }
        }
  
 +      if (fast_forward_only)
 +              die("Not possible to fast-forward, aborting.");
 +
        /* We are going to make a new commit. */
        git_committer_info(IDENT_ERROR_ON_NO_NAME);