[PATCH v3 3/9] cherry-pick: add --skip-empty option

[Felipe Contreras <felipe.contreras@gmail.com>]

Pretty much what it says on the tin.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 Documentation/git-cherry-pick.txt   |  3 +++
 builtin/revert.c                    |  8 ++++++++
 sequencer.c                         |  6 ++++++
 sequencer.h                         |  1 +
 t/t3508-cherry-pick-many-commits.sh | 13 +++++++++++++
 5 files changed, 31 insertions(+)

diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index c205d23..fccd936 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -129,6 +129,9 @@ effect to your index in a row.
 	redundant commits are ignored.  This option overrides that behavior and
 	creates an empty commit object.  Implies `--allow-empty`.
 
+--skip-empty::
+	Instead of failing, skip commits that are or become empty.
+
 --strategy=<strategy>::
 	Use the given merge strategy.  Should only be used once.
 	See the MERGE STRATEGIES section in linkgit:git-merge[1]
diff --git a/builtin/revert.c b/builtin/revert.c
index 0401fdb..5a8453d 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -118,6 +118,7 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 		OPT_END(),
 		OPT_END(),
 		OPT_END(),
+		OPT_END(),
 	};
 
 	if (opts->action == REPLAY_PICK) {
@@ -127,6 +128,7 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 			OPT_BOOLEAN(0, "allow-empty", &opts->allow_empty, N_("preserve initially empty commits")),
 			OPT_BOOLEAN(0, "allow-empty-message", &opts->allow_empty_message, N_("allow commits with empty messages")),
 			OPT_BOOLEAN(0, "keep-redundant-commits", &opts->keep_redundant_commits, N_("keep redundant, empty commits")),
+			OPT_BOOLEAN(0, "skip-empty", &opts->skip_empty, N_("skip empty commits")),
 			OPT_END(),
 		};
 		if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
@@ -144,6 +146,12 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 				"--abort", rollback,
 				NULL);
 
+	verify_opt_mutually_compatible(me,
+				"--allow-empty", opts->allow_empty,
+				"--skip-empty", opts->skip_empty,
+				"--keep-redundant-commits", opts->keep_redundant_commits,
+				NULL);
+
 	/* implies allow_empty */
 	if (opts->keep_redundant_commits)
 		opts->allow_empty = 1;
diff --git a/sequencer.c b/sequencer.c
index f7be7d8..d3c7d72 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -627,6 +627,12 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 		goto leave;
 	}
 
+	if (opts->skip_empty && is_index_unchanged() == 1) {
+		warning(_("skipping %s... %s"),
+			find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
+			msg.subject);
+		goto leave;
+	}
 	allow = allow_empty(opts, commit);
 	if (allow < 0) {
 		res = allow;
diff --git a/sequencer.h b/sequencer.h
index 1fc22dc..3b04844 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -34,6 +34,7 @@ struct replay_opts {
 	int allow_empty;
 	int allow_empty_message;
 	int keep_redundant_commits;
+	int skip_empty;
 
 	int mainline;
 
diff --git a/t/t3508-cherry-pick-many-commits.sh b/t/t3508-cherry-pick-many-commits.sh
index 19c99d7..3dc19c6 100755
--- a/t/t3508-cherry-pick-many-commits.sh
+++ b/t/t3508-cherry-pick-many-commits.sh
@@ -187,4 +187,17 @@ test_expect_success 'cherry-pick --stdin works' '
 	check_head_differs_from fourth
 '
 
+test_expect_success 'cherry-pick skip empty' '
+	git clean -fxd &&
+	git checkout -b empty fourth &&
+	git commit --allow-empty -m empty &&
+	test_commit ontop &&
+	git checkout -f master &&
+	git reset --hard fourth &&
+	git cherry-pick --skip-empty fourth..empty &&
+	echo ontop > expected &&
+	git log --format=%s fourth..HEAD > actual
+	test_cmp expected actual
+'
+
 test_done
-- 
1.8.3.698.g079b096