From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 10 Nov 2009 20:32:59 +0000 (-0800)
Subject: Merge branch 'bg/merge-ff-only'
X-Git-Tag: v1.6.6-rc0~62
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/3cc335181fdeba6cb25e9a6e55217b2e8d18e6b1?ds=inline;hp=-c

Merge branch 'bg/merge-ff-only'

* bg/merge-ff-only:
Teach 'git merge' and 'git pull' the option --ff-only
---

3cc335181fdeba6cb25e9a6e55217b2e8d18e6b1
diff --combined Documentation/merge-options.txt
index 48d04a5d88,27a9a8489c..fec3394305
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@@ -1,42 -1,43 +1,42 @@@
 --q::
 ---quiet::
 -	Operate quietly.
 -
 --v::
 ---verbose::
 -	Be verbose.
 -
 ---stat::
 -	Show a diffstat at the end of the merge. The diffstat is also
 -	controlled by the configuration option merge.stat.
 -
 --n::
 ---no-stat::
 -	Do not show a diffstat at the end of the merge.
 +--commit::
 +--no-commit::
 +	Perform the merge and commit the result. This option can
 +	be used to override --no-commit.
 ++
 +With --no-commit perform the merge but pretend the merge
 +failed and do not autocommit, to give the user a chance to
 +inspect and further tweak the merge result before committing.
  
 ---summary::
 ---no-summary::
 -	Synonyms to --stat and --no-stat; these are deprecated and will be
 -	removed in the future.
 +--ff::
 +--no-ff::
 +	Do not generate a merge commit if the merge resolved as
 +	a fast-forward, only update the branch pointer. This is
 +	the default behavior of git-merge.
 ++
 +With --no-ff Generate a merge commit even if the merge
 +resolved as a fast-forward.
  
  --log::
 +--no-log::
  	In addition to branch names, populate the log message with
  	one-line descriptions from the actual commits that are being
  	merged.
 ++
 +With --no-log do not list one-line descriptions from the
 +actual commits being merged.
  
 ---no-log::
 -	Do not list one-line descriptions from the actual commits being
 -	merged.
 -
 ---no-commit::
 -	Perform the merge but pretend the merge failed and do
 -	not autocommit, to give the user a chance to inspect and
 -	further tweak the merge result before committing.
  
 ---commit::
 -	Perform the merge and commit the result. This option can
 -	be used to override --no-commit.
 +--stat::
 +-n::
 +--no-stat::
 +	Show a diffstat at the end of the merge. The diffstat is also
 +	controlled by the configuration option merge.stat.
 ++
 +With -n or --no-stat do not show a diffstat at the end of the
 +merge.
  
  --squash::
 +--no-squash::
  	Produce the working tree and index state as if a real
  	merge happened (except for the merge information),
  	but do not actually make a commit or
@@@ -45,10 -46,25 +45,15 @@@
  	commit.  This allows you to create a single commit on
  	top of the current branch whose effect is the same as
  	merging another branch (or more in case of an octopus).
 -
 ---no-squash::
 -	Perform the merge and commit the result. This option can
 -	be used to override --squash.
 -
 ---no-ff::
 -	Generate a merge commit even if the merge resolved as a
 -	fast-forward.
 -
 ---ff::
 -	Do not generate a merge commit if the merge resolved as
 -	a fast-forward, only update the branch pointer. This is
 -	the default behavior of git-merge.
 ++
 +With --no-squash perform the merge and commit the result. This
 +option can be used to override --squash.
  
+ --ff-only::
+ 	Refuse to merge and exit with a non-zero status unless the
+ 	current `HEAD` is already up-to-date or the merge can be
+ 	resolved as a fast-forward.
+ 
  -s <strategy>::
  --strategy=<strategy>::
  	Use the given merge strategy; can be supplied more than
@@@ -56,16 -72,3 +61,16 @@@
  	If there is no `-s` option, a built-in list of strategies
  	is used instead ('git-merge-recursive' when merging a single
  	head, 'git-merge-octopus' otherwise).
 +
 +--summary::
 +--no-summary::
 +	Synonyms to --stat and --no-stat; these are deprecated and will be
 +	removed in the future.
 +
 +-q::
 +--quiet::
 +	Operate quietly.
 +
 +-v::
 +--verbose::
 +	Be verbose.
diff --combined builtin-merge.c
index c69a3051f3,5e8c4b5e4b..1ff7b15803
--- a/builtin-merge.c
+++ b/builtin-merge.c
@@@ -43,6 -43,7 +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;
@@@ -167,6 -168,8 +168,8 @@@ static struct option builtin_merge_opti
  		"perform a commit if the merge succeeds (default)"),
  	OPT_BOOLEAN(0, "ff", &allow_fast_forward,
  		"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",
@@@ -264,7 -267,6 +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);
@@@ -286,15 -288,13 +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");
@@@ -877,6 -877,9 +880,9 @@@ int cmd_merge(int argc, const char **ar
  		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);
@@@ -1043,7 -1046,7 +1049,7 @@@
  		 * 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");
@@@ -1082,6 -1085,9 +1088,9 @@@
  		}
  	}
  
+ 	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);