[PATCH v2 2/2] rebase: remember fixup -c after skipping fixup/squash

From: Phillip Wood <[email protected]>

When the final command in a chain of "fixup" and "squash" commands
is skipped, we should prompt the user to edit the commit message
if the chain contains a "fixup -c" command that was not skipped.
Unfortunately, commit_staged_changes() only looks for completed "squash"
commands and so does not prompt the user to edit the message. Fix
this by recording whether a fixup command has the "-c" flag set and
then checking whether we have seen either a "fixup -c" or a "squash"
command. Add regression tests for skipping a command in the middle
of the chain (which currently works but has no test coverage), and
for skipping the final command (which is fixed by this patch).

Signed-off-by: Phillip Wood <[email protected]>
---
 sequencer.c                     | 20 +++++++++++---
 t/t3437-rebase-fixup-options.sh | 47 +++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 4640ee9b7f5..1a0a283b42c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1924,6 +1924,13 @@ static int seen_squash(struct replay_ctx *ctx)
 {
 	return starts_with(ctx->current_fixups.buf, "squash") ||
 		strstr(ctx->current_fixups.buf, "\nsquash");
+}
+
+/* Does the current fixup chain contain a "fixup -c" command? */
+static int seen_fixup_edit_msg(struct replay_ctx *ctx)
+{
+	return starts_with(ctx->current_fixups.buf, "fixup -c") ||
+		strstr(ctx->current_fixups.buf, "\nfixup -c");
 }
 
 static void update_comment_bufs(struct strbuf *buf1, struct strbuf *buf2, int n)
@@ -2148,9 +2155,14 @@ static int update_squash_messages(struct repository *r,
 	strbuf_release(&buf);
 
 	if (!res) {
-		strbuf_addf(&ctx->current_fixups, "%s%s %s",
+		const char *fixup_flag = "";
+
+		if (is_fixup_flag(command, flag) && (flag & TODO_EDIT_FIXUP_MSG))
+			fixup_flag = " -c";
+
+		strbuf_addf(&ctx->current_fixups, "%s%s%s %s",
 			    ctx->current_fixups.len ? "\n" : "",
-			    command_to_string(command),
+			    command_to_string(command), fixup_flag,
 			    oid_to_hex(&commit->object.oid));
 		res = write_message(ctx->current_fixups.buf,
 				    ctx->current_fixups.len,
@@ -5391,8 +5403,8 @@ static int commit_staged_changes(struct repository *r,
 				 * message, no need to bother the user with
 				 * opening the commit message in the editor.
 				 */
-				if (!starts_with(p, "squash ") &&
-				    !strstr(p, "\nsquash "))
+				if (!seen_squash(ctx) &&
+				    !seen_fixup_edit_msg(ctx))
 					flags = (flags & ~EDIT_MSG) | CLEANUP_MSG;
 			} else if (is_fixup(peek_command(todo_list, 0))) {
 				/*
diff --git a/t/t3437-rebase-fixup-options.sh b/t/t3437-rebase-fixup-options.sh
index 5d306a47692..a4b2a631654 100755
--- a/t/t3437-rebase-fixup-options.sh
+++ b/t/t3437-rebase-fixup-options.sh
@@ -184,6 +184,53 @@ test_expect_success 'multiple fixup -c opens editor once' '
 	get_author HEAD >actual-author &&
 	test_cmp expected-author actual-author &&
 	test_commit_message HEAD expected-message
+'
+
+test_expect_success 'fixup -c is remembered after skipping final fixup' '
+	test_when_finished "test_might_fail git rebase --abort" &&
+	cat >todo <<-\EOF &&
+	pick B
+	fixup -c A1
+	fixup A3
+	EOF
+	(
+		set_fake_editor &&
+		set_replace_editor todo &&
+		test_must_fail git rebase -i A A &&
+		git show && cat .git/rebase-merge/message-squash &&
+		FAKE_COMMIT_AMEND=edited git rebase --skip
+	) &&
+	test_commit_message HEAD <<-\EOF
+	new subject
+
+	new
+	body
+
+	edited
+	EOF
+'
+test_expect_success 'fixup -c is remembered after skipping later fixup' '
+	test_when_finished "test_might_fail git rebase --abort" &&
+	cat >todo <<-\EOF &&
+	pick B
+	fixup -c A1
+	fixup A3
+	fixup A2
+	EOF
+	(
+		set_fake_editor &&
+		set_replace_editor todo &&
+		test_must_fail git rebase -i A A &&
+		FAKE_COMMIT_AMEND=edited git rebase --skip
+	) &&
+	test_commit_message HEAD <<-\EOF
+	new subject
+
+	new
+	body
+
+	edited
+	EOF
 '
 
 test_expect_success 'sequence squash, fixup & fixup -c gives combined message' '
-- 
2.54.0.200.gfd8d68259e3