Merge branch 'en/rebase-merge-on-sequencer'

"git rebase --merge" as been reimplemented by reusing the internal
machinery used for "git rebase -i".

* en/rebase-merge-on-sequencer:
  rebase: implement --merge via the interactive machinery
  rebase: define linearization ordering and enforce it
  git-legacy-rebase: simplify unnecessary triply-nested if
  git-rebase, sequencer: extend --quiet option for the interactive machinery
  am, rebase--merge: do not overlook --skip'ed commits with post-rewrite
  t5407: add a test demonstrating how interactive handles --skip differently
  rebase: fix incompatible options error message
  rebase: make builtin and legacy script error messages the same

2 files changed, 19 insertions, 20 deletions

diff --git a/builtin/am.c b/builtin/am.c
index 95370313b6..6d1c6d3da9 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -2000,6 +2000,15 @@ static void am_skip(struct am_state *state)
 	if (clean_index(&head, &head))
 		die(_("failed to clean index"));
 
+	if (state->rebasing) {
+		FILE *fp = xfopen(am_path(state, "rewritten"), "a");
+
+		assert(!is_null_oid(&state->orig_commit));
+		fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
+		fprintf(fp, "%s\n", oid_to_hex(&head));
+		fclose(fp);
+	}
+
 	am_next(state);
 	am_load(state);
 	am_run(state, 0);
diff --git a/builtin/rebase.c b/builtin/rebase.c
index fdeb41e899..3f9b26f729 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -123,7 +123,7 @@ static void imply_interactive(struct rebase_options *opts, const char *option)
 	case REBASE_PRESERVE_MERGES:
 		break;
 	case REBASE_MERGE:
-		/* we silently *upgrade* --merge to --interactive if needed */
+		/* we now implement --merge via --interactive */
 	default:
 		opts->type = REBASE_INTERACTIVE; /* implied */
 		break;
@@ -186,10 +186,7 @@ static int read_basic_state(struct rebase_options *opts)
 	if (get_oid(buf.buf, &opts->orig_head))
 		return error(_("invalid orig-head: '%s'"), buf.buf);
 
-	strbuf_reset(&buf);
-	if (read_one(state_dir_path("quiet", opts), &buf))
-		return -1;
-	if (buf.len)
+	if (file_exists(state_dir_path("quiet", opts)))
 		opts->flags &= ~REBASE_NO_QUIET;
 	else
 		opts->flags |= REBASE_NO_QUIET;
@@ -488,10 +485,6 @@ static int run_specific_rebase(struct rebase_options *opts)
 		backend = "git-rebase--am";
 		backend_func = "git_rebase__am";
 		break;
-	case REBASE_MERGE:
-		backend = "git-rebase--merge";
-		backend_func = "git_rebase__merge";
-		break;
 	case REBASE_PRESERVE_MERGES:
 		backend = "git-rebase--preserve-merges";
 		backend_func = "git_rebase__preserve_merges";
@@ -1233,6 +1226,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		}
 	}
 
+	if (options.type == REBASE_MERGE)
+		imply_interactive(&options, "--merge");
+
 	if (options.root && !options.onto_name)
 		imply_interactive(&options, "--root without --onto");
 
@@ -1265,14 +1261,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 				break;
 
 		if (is_interactive(&options) && i >= 0)
-			die(_("error: cannot combine interactive options "
-			      "(--interactive, --exec, --rebase-merges, "
-			      "--preserve-merges, --keep-empty, --root + "
-			      "--onto) with am options (%s)"), buf.buf);
-		if (options.type == REBASE_MERGE && i >= 0)
-			die(_("error: cannot combine merge options (--merge, "
-			      "--strategy, --strategy-option) with am options "
-			      "(%s)"), buf.buf);
+			die(_("cannot combine am options with either "
+			      "interactive or merge options"));
 	}
 
 	if (options.signoff) {
@@ -1290,7 +1280,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		 *       git-rebase.txt caveats with "unless you know what you are doing"
 		 */
 		if (options.rebase_merges)
-			die(_("error: cannot combine '--preserve-merges' with "
+			die(_("cannot combine '--preserve-merges' with "
 			      "'--rebase-merges'"));
 
 		if (options.reschedule_failed_exec)
@@ -1300,10 +1290,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	if (options.rebase_merges) {
 		if (strategy_options.nr)
-			die(_("error: cannot combine '--rebase-merges' with "
+			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy-option'"));
 		if (options.strategy)
-			die(_("error: cannot combine '--rebase-merges' with "
+			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy'"));
 	}