From ebddf393964120628f60f6f5e435cde87cc209c6 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 4 May 2018 01:01:23 +0200 Subject: [PATCH] sequencer: allow introducing new root commits In the context of the new --rebase-merges mode, which was designed specifically to allow for changing the existing branch topology liberally, a user may want to extract commits into a completely fresh branch that starts with a newly-created root commit. This is now possible by inserting the command `reset [new root]` before `pick`ing the commit that wants to become a root commit. Example: reset [new root] pick 012345 a commit that is about to become a root commit pick 234567 this commit will have the previous one as parent This does not conflict with other uses of the `reset` command because `[new root]` is not (part of) a valid ref name: both the opening bracket as well as the space are illegal in ref names. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- sequencer.c | 40 ++++++++++++++++++++++++++++------------ t/t3430-rebase-merges.sh | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+), 12 deletions(-) diff --git a/sequencer.c b/sequencer.c index 8eddda681d..a7832399b1 100644 --- a/sequencer.c +++ b/sequencer.c @@ -2747,18 +2747,34 @@ static int do_reset(const char *name, int len, struct replay_opts *opts) if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) return -1; - /* Determine the length of the label */ - for (i = 0; i < len; i++) - if (isspace(name[i])) - len = i; - - strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name); - if (get_oid(ref_name.buf, &oid) && - get_oid(ref_name.buf + strlen("refs/rewritten/"), &oid)) { - error(_("could not read '%s'"), ref_name.buf); - rollback_lock_file(&lock); - strbuf_release(&ref_name); - return -1; + if (len == 10 && !strncmp("[new root]", name, len)) { + if (!opts->have_squash_onto) { + const char *hex; + if (commit_tree("", 0, the_hash_algo->empty_tree, + NULL, &opts->squash_onto, + NULL, NULL)) + return error(_("writing fake root commit")); + opts->have_squash_onto = 1; + hex = oid_to_hex(&opts->squash_onto); + if (write_message(hex, strlen(hex), + rebase_path_squash_onto(), 0)) + return error(_("writing squash-onto")); + } + oidcpy(&oid, &opts->squash_onto); + } else { + /* Determine the length of the label */ + for (i = 0; i < len; i++) + if (isspace(name[i])) + len = i; + + strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name); + if (get_oid(ref_name.buf, &oid) && + get_oid(ref_name.buf + strlen("refs/rewritten/"), &oid)) { + error(_("could not read '%s'"), ref_name.buf); + rollback_lock_file(&lock); + strbuf_release(&ref_name); + return -1; + } } memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts)); diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh index 3d4dfdf7be..35260862fc 100755 --- a/t/t3430-rebase-merges.sh +++ b/t/t3430-rebase-merges.sh @@ -241,4 +241,38 @@ test_expect_success 'refuse to merge ancestors of HEAD' ' test_cmp_rev HEAD $before ' +test_expect_success 'root commits' ' + git checkout --orphan unrelated && + (GIT_AUTHOR_NAME="Parsnip" GIT_AUTHOR_EMAIL="root@example.com" \ + test_commit second-root) && + test_commit third-root && + cat >script-from-scratch <<-\EOF && + pick third-root + label first-branch + reset [new root] + pick second-root + merge first-branch # Merge the 3rd root + EOF + test_config sequence.editor \""$PWD"/replace-editor.sh\" && + test_tick && + git rebase -i --force --root -r && + test "Parsnip" = "$(git show -s --format=%an HEAD^)" && + test $(git rev-parse second-root^0) != $(git rev-parse HEAD^) && + test $(git rev-parse second-root:second-root.t) = \ + $(git rev-parse HEAD^:second-root.t) && + test_cmp_graph HEAD <<-\EOF && + * Merge the 3rd root + |\ + | * third-root + * second-root + EOF + + : fast forward if possible && + before="$(git rev-parse --verify HEAD)" && + test_might_fail git config --unset sequence.editor && + test_tick && + git rebase -i --root -r && + test_cmp_rev HEAD $before +' + test_done -- 2.39.2