commit 82d979c595ed3516ee1dbff4500ccd8cf84848ce
from: Josh Rickmar <jrick@zettaport.com>
via: Thomas Adam <thomas@xteddy.org>
date: Thu Nov 04 17:40:50 2021 UTC

switch branches during noop rebases

Always update to the specified branch even if the branch is already
rebased (no commits needed to be rebased, and the branch does not need
a fast forward).  With the old behavior of erroring and staying on the
current branch, I sometimes found myself ignoring the error message,
treating it as information and assuming the branch update, and later
on committing on top of origin/main instead of the main branch.

feedback and ok stsp

commit - 5d7e2cd05a57bd094a600963db2c19da60278dae
commit + 82d979c595ed3516ee1dbff4500ccd8cf84848ce
blob - 02099e4c91aac5a1e9d1803898d1c74c33234d0d
blob + 389f9d08088c16749e26653373e02b47dbea55f0
--- got/got.c
+++ got/got.c
@@ -9147,12 +9147,41 @@ cmd_rebase(int argc, char *argv[])
 				goto done;
 			error = NULL;
 		} else {
-			static char msg[128];
-			snprintf(msg, sizeof(msg),
-			    "%s is already based on %s",
+			struct got_pathlist_head paths;
+			printf("%s is already based on %s\n",
 			    got_ref_get_name(branch),
 			    got_worktree_get_head_ref_name(worktree));
-			error = got_error_msg(GOT_ERR_SAME_BRANCH, msg);
+			error = switch_head_ref(branch, branch_head_commit_id,
+			    worktree, repo);
+			if (error)
+				goto done;
+			error = got_worktree_set_base_commit_id(worktree, repo,
+			    branch_head_commit_id);
+			if (error)
+				goto done;
+			TAILQ_INIT(&paths);
+			error = got_pathlist_append(&paths, "", NULL);
+			if (error)
+				goto done;
+			error = got_worktree_checkout_files(worktree,
+			    &paths, repo, update_progress, &upa,
+			    check_cancelled, NULL);
+			got_pathlist_free(&paths);
+			if (error)
+				goto done;
+			if (upa.did_something) {
+				char *id_str;
+				error = got_object_id_str(&id_str,
+				    branch_head_commit_id);
+				if (error)
+					goto done;
+				printf("Updated to %s: %s\n",
+				    got_worktree_get_head_ref_name(worktree),
+				    id_str);
+				free(id_str);
+			} else
+				printf("Already up-to-date\n");
+			print_update_progress_stats(&upa);
 			goto done;
 		}
 		error = got_worktree_rebase_prepare(&new_base_branch,
blob - 0531881d4d4855f22d5d2acb605d1575c537a94d
blob + d37274f3b583e7a546109ca74441188e9e6ee40f
--- regress/cmdline/rebase.sh
+++ regress/cmdline/rebase.sh
@@ -246,11 +246,18 @@ test_rebase_ancestry_check() {
 	(cd $testroot/repo && git checkout -q -b newbranch)
 	echo "modified delta on branch" > $testroot/repo/gamma/delta
 	git_commit $testroot/repo -m "committing to delta on newbranch"
+	local newbranch_id=`git_show_head $testroot/repo`
 
 	(cd $testroot/wt && got rebase newbranch > $testroot/stdout \
 		2> $testroot/stderr)
 
-	echo -n > $testroot/stdout.expected
+	echo "refs/heads/newbranch is already based on refs/heads/master" \
+		> $testroot/stdout.expected
+	echo "Switching work tree from refs/heads/master to refs/heads/newbranch" \
+		>> $testroot/stdout.expected
+	echo "U  gamma/delta" >> $testroot/stdout.expected
+	echo "Updated to refs/heads/newbranch: ${newbranch_id}" \
+		>> $testroot/stdout.expected
 	cmp -s $testroot/stdout.expected $testroot/stdout
 	ret="$?"
 	if [ "$ret" != "0" ]; then
@@ -259,8 +266,7 @@ test_rebase_ancestry_check() {
 		return 1
 	fi
 
-	echo "got: refs/heads/newbranch is already based on refs/heads/master" \
-		> $testroot/stderr.expected
+	echo -n > $testroot/stderr.expected
 	cmp -s $testroot/stderr.expected $testroot/stderr
 	ret="$?"
 	if [ "$ret" != "0" ]; then