Merge branch 'pw/advise-rebase-skip'

The mechanism to prevent "git commit" from making an empty commit
or amending during an interrupted cherry-pick was broken during the
rewrite of "git rebase" in C, which has been corrected.

* pw/advise-rebase-skip:
  commit: give correct advice for empty commit during a rebase
  commit: encapsulate determine_whence() for sequencer
  commit: use enum value for multiple cherry-picks
  sequencer: write CHERRY_PICK_HEAD for reword and edit
  cherry-pick: check commit error messages
  cherry-pick: add test for `--skip` advice in `git commit`
  t3404: use test_cmp_rev

Author: gitster

builtin/commit.c

@@ -59,6 +59,9 @@ N_("The previous cherry-pick is now empty, possibly due to conflict resolution.\
 "    git commit --allow-empty\n"
 "\n");
 
+static const char empty_rebase_pick_advice[] =
+N_("Otherwise, please use 'git rebase --skip'\n");
+
 static const char empty_cherry_pick_advice_single[] =
 N_("Otherwise, please use 'git cherry-pick --skip'\n");
 
@@ -122,7 +125,6 @@ static enum commit_msg_cleanup_mode cleanup_mode;
 static const char *cleanup_arg;
 
 static enum commit_whence whence;
-static int sequencer_in_use;
 static int use_editor = 1, include_status = 1;
 static int have_option_m;
 static struct strbuf message = STRBUF_INIT;
@@ -179,12 +181,7 @@ static void determine_whence(struct wt_status *s)
 {
 	if (file_exists(git_path_merge_head(the_repository)))
 		whence = FROM_MERGE;
-	else if (file_exists(git_path_cherry_pick_head(the_repository))) {
-		whence = FROM_CHERRY_PICK;
-		if (file_exists(git_path_seq_dir()))
-			sequencer_in_use = 1;
-	}
-	else
+	else if (!sequencer_determine_whence(the_repository, &whence))
 		whence = FROM_COMMIT;
 	if (s)
 		s->whence = whence;
@@ -477,8 +474,10 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 	if (whence != FROM_COMMIT) {
 		if (whence == FROM_MERGE)
 			die(_("cannot do a partial commit during a merge."));
-		else if (whence == FROM_CHERRY_PICK)
+		else if (is_from_cherry_pick(whence))
 			die(_("cannot do a partial commit during a cherry-pick."));
+		else if (is_from_rebase(whence))
+			die(_("cannot do a partial commit during a rebase."));
 	}
 
 	if (list_paths(&partial, !current_head ? NULL : "HEAD", &pathspec))
@@ -795,7 +794,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	 */
 	else if (whence == FROM_MERGE)
 		hook_arg1 = "merge";
-	else if (whence == FROM_CHERRY_PICK) {
+	else if (is_from_cherry_pick(whence) || whence == FROM_REBASE_PICK) {
 		hook_arg1 = "commit";
 		hook_arg2 = "CHERRY_PICK_HEAD";
 	}
@@ -973,12 +972,15 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		run_status(stdout, index_file, prefix, 0, s);
 		if (amend)
 			fputs(_(empty_amend_advice), stderr);
-		else if (whence == FROM_CHERRY_PICK) {
+		else if (is_from_cherry_pick(whence) ||
+			 whence == FROM_REBASE_PICK) {
 			fputs(_(empty_cherry_pick_advice), stderr);
-			if (!sequencer_in_use)
+			if (whence == FROM_CHERRY_PICK_SINGLE)
 				fputs(_(empty_cherry_pick_advice_single), stderr);
-			else
+			else if (whence == FROM_CHERRY_PICK_MULTI)
 				fputs(_(empty_cherry_pick_advice_multi), stderr);
+			else
+				fputs(_(empty_rebase_pick_advice), stderr);
 		}
 		return 0;
 	}
@@ -1181,8 +1183,10 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	if (amend && whence != FROM_COMMIT) {
 		if (whence == FROM_MERGE)
 			die(_("You are in the middle of a merge -- cannot amend."));
-		else if (whence == FROM_CHERRY_PICK)
+		else if (is_from_cherry_pick(whence))
 			die(_("You are in the middle of a cherry-pick -- cannot amend."));
+		else if (whence == FROM_REBASE_PICK)
+			die(_("You are in the middle of a rebase -- cannot amend."));
 	}
 	if (fixup_message && squash_message)
 		die(_("Options --squash and --fixup cannot be used together"));
@@ -1204,7 +1208,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 		use_message = edit_message;
 	if (amend && !use_message && !fixup_message)
 		use_message = "HEAD";
-	if (!use_message && whence != FROM_CHERRY_PICK && renew_authorship)
+	if (!use_message && !is_from_cherry_pick(whence) &&
+	    !is_from_rebase(whence) && renew_authorship)
 		die(_("--reset-author can be used only with -C, -c or --amend."));
 	if (use_message) {
 		use_message_buffer = read_commit_message(use_message);
@@ -1213,7 +1218,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 			author_message_buffer = use_message_buffer;
 		}
 	}
-	if (whence == FROM_CHERRY_PICK && !renew_authorship) {
+	if ((is_from_cherry_pick(whence) || whence == FROM_REBASE_PICK) &&
+	    !renew_authorship) {
 		author_message = "CHERRY_PICK_HEAD";
 		author_message_buffer = read_commit_message(author_message);
 	}
@@ -1631,8 +1637,10 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 			reduce_heads_replace(&parents);
 	} else {
 		if (!reflog_msg)
-			reflog_msg = (whence == FROM_CHERRY_PICK)
+			reflog_msg = is_from_cherry_pick(whence)
 					? "commit (cherry-pick)"
+					: is_from_rebase(whence)
+					? "commit (rebase)"
 					: "commit";
 		commit_list_insert(current_head, &parents);
 	}

sequencer.c

@@ -40,7 +40,7 @@ static const char cherry_picked_prefix[] = "(cherry picked from commit ";
 
 GIT_PATH_FUNC(git_path_commit_editmsg, "COMMIT_EDITMSG")
 
-GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
+static GIT_PATH_FUNC(git_path_seq_dir, "sequencer")
 
 static GIT_PATH_FUNC(git_path_todo_file, "sequencer/todo")
 static GIT_PATH_FUNC(git_path_opts_file, "sequencer/opts")
@@ -1433,9 +1433,19 @@ static int try_to_commit(struct repository *r,
 	return res;
 }
 
+static int write_rebase_head(struct object_id *oid)
+{
+	if (update_ref("rebase", "REBASE_HEAD", oid,
+		       NULL, REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
+		return error(_("could not update %s"), "REBASE_HEAD");
+
+	return 0;
+}
+
 static int do_commit(struct repository *r,
 		     const char *msg_file, const char *author,
-		     struct replay_opts *opts, unsigned int flags)
+		     struct replay_opts *opts, unsigned int flags,
+		     struct object_id *oid)
 {
 	int res = 1;
 
@@ -1460,8 +1470,12 @@ static int do_commit(struct repository *r,
 			return res;
 		}
 	}
-	if (res == 1)
+	if (res == 1) {
+		if (is_rebase_i(opts) && oid)
+			if (write_rebase_head(oid))
+			    return -1;
 		return run_git_commit(r, msg_file, opts, flags);
+	}
 
 	return res;
 }
@@ -1929,7 +1943,9 @@ static int do_pick_commit(struct repository *r,
 	 * However, if the merge did not even start, then we don't want to
 	 * write it at all.
 	 */
-	if (command == TODO_PICK && !opts->no_commit && (res == 0 || res == 1) &&
+	if ((command == TODO_PICK || command == TODO_REWORD ||
+	     command == TODO_EDIT) && !opts->no_commit &&
+	    (res == 0 || res == 1) &&
 	    update_ref(NULL, "CHERRY_PICK_HEAD", &commit->object.oid, NULL,
 		       REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
 		res = -1;
@@ -1965,7 +1981,8 @@ static int do_pick_commit(struct repository *r,
 	} /* else allow == 0 and there's nothing special to do */
 	if (!opts->no_commit && !drop_commit) {
 		if (author || command == TODO_REVERT || (flags & AMEND_MSG))
-			res = do_commit(r, msg_file, author, opts, flags);
+			res = do_commit(r, msg_file, author, opts, flags,
+					commit? &commit->object.oid : NULL);
 		else
 			res = error(_("unable to parse commit author"));
 		*check_todo = !!(flags & EDIT_MSG);
@@ -3000,9 +3017,7 @@ static int make_patch(struct repository *r,
 	p = short_commit_name(commit);
 	if (write_message(p, strlen(p), rebase_path_stopped_sha(), 1) < 0)
 		return -1;
-	if (update_ref("rebase", "REBASE_HEAD", &commit->object.oid,
-		       NULL, REF_NO_DEREF, UPDATE_REFS_MSG_ON_ERR))
-		res |= error(_("could not update %s"), "REBASE_HEAD");
+	res |= write_rebase_head(&commit->object.oid);
 
 	strbuf_addf(&buf, "%s/patch", get_dir(opts));
 	memset(&log_tree_opt, 0, sizeof(log_tree_opt));
@@ -5315,3 +5330,24 @@ int todo_list_rearrange_squash(struct todo_list *todo_list)
 
 	return 0;
 }
+
+int sequencer_determine_whence(struct repository *r, enum commit_whence *whence)
+{
+	if (file_exists(git_path_cherry_pick_head(r))) {
+		struct object_id cherry_pick_head, rebase_head;
+
+		if (file_exists(git_path_seq_dir()))
+			*whence = FROM_CHERRY_PICK_MULTI;
+		if (file_exists(rebase_path()) &&
+		    !get_oid("REBASE_HEAD", &rebase_head) &&
+		    !get_oid("CHERRY_PICK_HEAD", &cherry_pick_head) &&
+		    oideq(&rebase_head, &cherry_pick_head))
+			*whence = FROM_REBASE_PICK;
+		else
+			*whence = FROM_CHERRY_PICK_SINGLE;
+
+		return 1;
+	}
+
+	return 0;
+}

sequencer.h

@@ -3,12 +3,12 @@
 
 #include "cache.h"
 #include "strbuf.h"
+#include "wt-status.h"
 
 struct commit;
 struct repository;
 
 const char *git_path_commit_editmsg(void);
-const char *git_path_seq_dir(void);
 const char *rebase_path_todo(void);
 const char *rebase_path_todo_backup(void);
 const char *rebase_path_dropped(void);
@@ -206,4 +206,5 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 void sequencer_post_commit_cleanup(struct repository *r, int verbose);
 int sequencer_get_last_command(struct repository* r,
 			       enum replay_action *action);
+int sequencer_determine_whence(struct repository *r, enum commit_whence *whence);
 #endif /* SEQUENCER_H */

t/t3403-rebase-skip.sh

@@ -29,6 +29,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m reverted-goodbye &&
 	git tag reverted-goodbye &&
+	git checkout goodbye &&
+	test_tick &&
+	GIT_AUTHOR_NAME="Another Author" \
+		GIT_AUTHOR_EMAIL="[email protected]" \
+		git commit --amend --no-edit -m amended-goodbye &&
+	test_tick &&
+	git tag amended-goodbye &&
 
 	git checkout -f skip-reference &&
 	echo moo > hello &&
@@ -85,6 +92,78 @@ test_expect_success 'moved back to branch correctly' '
 
 test_debug 'gitk --all & sleep 1'
 
+test_expect_success 'correct advice upon picking empty commit' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -i --onto goodbye \
+		amended-goodbye^ amended-goodbye 2>err &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct authorship when committing empty pick' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -i --onto goodbye \
+		amended-goodbye^ amended-goodbye &&
+	git commit --allow-empty &&
+	git log --pretty=format:"%an <%ae>%n%ad%B" -1 amended-goodbye >expect &&
+	git log --pretty=format:"%an <%ae>%n%ad%B" -1 HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'correct advice upon rewording empty commit' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="reword 1" git rebase -i \
+			--onto goodbye amended-goodbye^ amended-goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct advice upon editing empty commit' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="edit 1" git rebase -i \
+			--onto goodbye amended-goodbye^ amended-goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct advice upon cherry-picking an empty commit during a rebase' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="1 exec_git_cherry-pick_amended-goodbye" \
+			git rebase -i goodbye^ goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
+	test_must_fail git commit 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err
+'
+
+test_expect_success 'correct advice upon multi cherry-pick picking an empty commit during a rebase' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="1 exec_git_cherry-pick_goodbye_amended-goodbye" \
+			git rebase -i goodbye^^ goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
+	test_must_fail git commit 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err
+'
+
 test_expect_success 'fixup that empties commit fails' '
 	test_when_finished "git rebase --abort" &&
 	(