Once upon a time, I dreamt of an interactive rebase that would not flatten branch structure, but instead recreate the commit topology faithfully. My original attempt was --preserve-merges, but that design was so limited that I did not even enable it in interactive mode. Subsequently, it *was* enabled in interactive mode, with the predictable consequences: as the --preserve-merges design does not allow for specifying the parents of merge commits explicitly, all the new commits' parents are defined *implicitly* by the previous commit history, and hence it is *not possible to even reorder commits*. This design flaw cannot be fixed. Not without a complete re-design, at least. This patch series offers such a re-design. Think of --recreate-merges as "--preserve-merges done right". It introduces new verbs for the todo list, `label`, `reset` and `merge`. For a commit topology like this: A - B - C \ / D the generated todo list would look like this: # branch D pick 0123 A label branch-point pick 1234 D label D reset branch-point pick 2345 B merge -C 3456 D # C There are more patches in the pipeline, based on this patch series, but left for later in the interest of reviewable patch series: one mini series to use the sequencer even for `git rebase -i --root`, and another one to add support for octopus merges to --recreate-merges. Changes since v3: - fixed a grammar error in "introduce the `merge` command"'s commit message. - fixed a couple of resource leaks in safe_append() and do_reset(), pointed out by Eric Sunshine. Johannes Schindelin (11): sequencer: avoid using errno clobbered by rollback_lock_file() sequencer: make rearrange_squash() a bit more obvious sequencer: introduce new commands to reset the revision sequencer: introduce the `merge` command sequencer: fast-forward merge commits, if possible rebase-helper --make-script: introduce a flag to recreate merges rebase: introduce the --recreate-merges option sequencer: make refs generated by the `label` command worktree-local sequencer: handle post-rewrite for merge commands pull: accept --rebase=recreate to recreate the branch topology rebase -i: introduce --recreate-merges=[no-]rebase-cousins Stefan Beller (1): git-rebase--interactive: clarify arguments Documentation/config.txt | 8 + Documentation/git-pull.txt | 5 +- Documentation/git-rebase.txt | 14 +- builtin/pull.c | 14 +- builtin/rebase--helper.c | 13 +- builtin/remote.c | 2 + contrib/completion/git-completion.bash | 4 +- git-rebase--interactive.sh | 22 +- git-rebase.sh | 16 + refs.c | 3 +- sequencer.c | 742 ++++++++++++++++++++++++++++++++- sequencer.h | 7 + t/t3430-rebase-recreate-merges.sh | 208 +++++++++ 13 files changed, 1027 insertions(+), 31 deletions(-) create mode 100755 t/t3430-rebase-recreate-merges.sh base-commit: e3a80781f5932f5fea12a49eb06f3ade4ed8945c Published-As: https://github.com/dscho/git/releases/tag/recreate-merges-v4 Fetch-It-Via: git fetch https://github.com/dscho/git recreate-merges-v4 Interdiff vs v3: diff --git a/Documentation/config.txt b/Documentation/config.txt index f57e9cf10ca..8c9adea0d0c 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -1058,6 +1058,10 @@ branch.<name>.rebase:: "git pull" is run. See "pull.rebase" for doing this in a non branch-specific manner. + +When recreate, also pass `--recreate-merges` along to 'git rebase' +so that locally committed merge commits will not be flattened +by running 'git pull'. ++ When preserve, also pass `--preserve-merges` along to 'git rebase' so that locally committed merge commits will not be flattened by running 'git pull'. @@ -2607,6 +2611,10 @@ pull.rebase:: pull" is run. See "branch.<name>.rebase" for setting this on a per-branch basis. + +When recreate, also pass `--recreate-merges` along to 'git rebase' +so that locally committed merge commits will not be flattened +by running 'git pull'. ++ When preserve, also pass `--preserve-merges` along to 'git rebase' so that locally committed merge commits will not be flattened by running 'git pull'. diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt index ce05b7a5b13..b4f9f057ea9 100644 --- a/Documentation/git-pull.txt +++ b/Documentation/git-pull.txt @@ -101,13 +101,16 @@ Options related to merging include::merge-options.txt[] -r:: ---rebase[=false|true|preserve|interactive]:: +--rebase[=false|true|recreate|preserve|interactive]:: When true, rebase the current branch on top of the upstream branch after fetching. If there is a remote-tracking branch corresponding to the upstream branch and the upstream branch was rebased since last fetched, the rebase uses that information to avoid rebasing non-local changes. + +When set to recreate, rebase with the `--recreate-merges` option passed +to `git rebase` so that locally created merge commits will not be flattened. ++ When set to preserve, rebase with the `--preserve-merges` option passed to `git rebase` so that locally created merge commits will not be flattened. + diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt index d713951b86a..c5a77599c47 100644 --- a/Documentation/git-rebase.txt +++ b/Documentation/git-rebase.txt @@ -373,6 +373,17 @@ The commit list format can be changed by setting the configuration option rebase.instructionFormat. A customized instruction format will automatically have the long commit hash prepended to the format. +--recreate-merges[=(rebase-cousins|no-rebase-cousins)]:: + Recreate merge commits instead of flattening the history by replaying + merges. Merge conflict resolutions or manual amendments to merge + commits are not recreated automatically, but have to be recreated + manually. ++ +By default, or when `no-rebase-cousins` was specified, commits which do not +have `<upstream>` as direct ancestor keep their original branch point. +If the `rebase-cousins` mode is turned on, such commits are rebased onto +`<upstream>` (or `<onto>`, if specified). + -p:: --preserve-merges:: Recreate merge commits instead of flattening the history by replaying @@ -775,7 +786,8 @@ BUGS The todo list presented by `--preserve-merges --interactive` does not represent the topology of the revision graph. Editing commits and rewording their commit messages should work fine, but attempts to -reorder commits tend to produce counterintuitive results. +reorder commits tend to produce counterintuitive results. Use +--recreate-merges for a more faithful representation. For example, an attempt to rearrange ------------ diff --git a/builtin/pull.c b/builtin/pull.c index 1876271af94..9da2cfa0bd3 100644 --- a/builtin/pull.c +++ b/builtin/pull.c @@ -27,14 +27,16 @@ enum rebase_type { REBASE_FALSE = 0, REBASE_TRUE, REBASE_PRESERVE, + REBASE_RECREATE, REBASE_INTERACTIVE }; /** * Parses the value of --rebase. If value is a false value, returns * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is - * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with - * a fatal error if fatal is true, otherwise returns REBASE_INVALID. + * "recreate", returns REBASE_RECREATE. If value is "preserve", returns + * REBASE_PRESERVE. If value is a invalid value, dies with a fatal error if + * fatal is true, otherwise returns REBASE_INVALID. */ static enum rebase_type parse_config_rebase(const char *key, const char *value, int fatal) @@ -47,6 +49,8 @@ static enum rebase_type parse_config_rebase(const char *key, const char *value, return REBASE_TRUE; else if (!strcmp(value, "preserve")) return REBASE_PRESERVE; + else if (!strcmp(value, "recreate")) + return REBASE_RECREATE; else if (!strcmp(value, "interactive")) return REBASE_INTERACTIVE; @@ -130,7 +134,7 @@ static struct option pull_options[] = { /* Options passed to git-merge or git-rebase */ OPT_GROUP(N_("Options related to merging")), { OPTION_CALLBACK, 'r', "rebase", &opt_rebase, - "false|true|preserve|interactive", + "false|true|recreate|preserve|interactive", N_("incorporate changes by rebasing rather than merging"), PARSE_OPT_OPTARG, parse_opt_rebase }, OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL, @@ -800,7 +804,9 @@ static int run_rebase(const struct object_id *curr_head, argv_push_verbosity(&args); /* Options passed to git-rebase */ - if (opt_rebase == REBASE_PRESERVE) + if (opt_rebase == REBASE_RECREATE) + argv_array_push(&args, "--recreate-merges"); + else if (opt_rebase == REBASE_PRESERVE) argv_array_push(&args, "--preserve-merges"); else if (opt_rebase == REBASE_INTERACTIVE) argv_array_push(&args, "--interactive"); diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c index ad074705bb5..5d1f12de57b 100644 --- a/builtin/rebase--helper.c +++ b/builtin/rebase--helper.c @@ -12,8 +12,8 @@ static const char * const builtin_rebase_helper_usage[] = { int cmd_rebase__helper(int argc, const char **argv, const char *prefix) { struct replay_opts opts = REPLAY_OPTS_INIT; - unsigned flags = 0, keep_empty = 0; - int abbreviate_commands = 0; + unsigned flags = 0, keep_empty = 0, recreate_merges = 0; + int abbreviate_commands = 0, rebase_cousins = -1; enum { CONTINUE = 1, ABORT, MAKE_SCRIPT, SHORTEN_OIDS, EXPAND_OIDS, CHECK_TODO_LIST, SKIP_UNNECESSARY_PICKS, REARRANGE_SQUASH, @@ -24,6 +24,9 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix) OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")), OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message, N_("allow commits with empty messages")), + OPT_BOOL(0, "recreate-merges", &recreate_merges, N_("recreate merge commits")), + OPT_BOOL(0, "rebase-cousins", &rebase_cousins, + N_("keep original branch points of cousins")), OPT_CMDMODE(0, "continue", &command, N_("continue rebase"), CONTINUE), OPT_CMDMODE(0, "abort", &command, N_("abort rebase"), @@ -57,8 +60,14 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix) flags |= keep_empty ? TODO_LIST_KEEP_EMPTY : 0; flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0; + flags |= recreate_merges ? TODO_LIST_RECREATE_MERGES : 0; + flags |= rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0; flags |= command == SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0; + if (rebase_cousins >= 0 && !recreate_merges) + warning(_("--[no-]rebase-cousins has no effect without " + "--recreate-merges")); + if (command == CONTINUE && argc == 1) return !!sequencer_continue(&opts); if (command == ABORT && argc == 1) diff --git a/builtin/remote.c b/builtin/remote.c index d95bf904c3b..b7d0f7ce596 100644 --- a/builtin/remote.c +++ b/builtin/remote.c @@ -306,6 +306,8 @@ static int config_read_branches(const char *key, const char *value, void *cb) info->rebase = v; else if (!strcmp(value, "preserve")) info->rebase = NORMAL_REBASE; + else if (!strcmp(value, "recreate")) + info->rebase = NORMAL_REBASE; else if (!strcmp(value, "interactive")) info->rebase = INTERACTIVE_REBASE; } diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash index 88813e91244..3d44cb6890c 100644 --- a/contrib/completion/git-completion.bash +++ b/contrib/completion/git-completion.bash @@ -2008,7 +2008,7 @@ _git_rebase () --*) __gitcomp " --onto --merge --strategy --interactive - --preserve-merges --stat --no-stat + --recreate-merges --preserve-merges --stat --no-stat --committer-date-is-author-date --ignore-date --ignore-whitespace --whitespace= --autosquash --no-autosquash @@ -2182,7 +2182,7 @@ _git_config () return ;; branch.*.rebase) - __gitcomp "false true preserve interactive" + __gitcomp "false true recreate preserve interactive" return ;; remote.pushdefault) diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh index a2659fea982..679d79e0d17 100644 --- a/git-rebase--interactive.sh +++ b/git-rebase--interactive.sh @@ -162,6 +162,12 @@ s, squash <commit> = use commit, but meld into previous commit f, fixup <commit> = like \"squash\", but discard this commit's log message x, exec <commit> = run command (the rest of the line) using shell d, drop <commit> = remove commit +l, label <label> = label current HEAD with a name +t, reset <label> = reset HEAD to a label +m, merge [-C <commit> | -c <commit>] <label> [# <oneline>] +. create a merge commit using the original merge commit's +. message (or the oneline, if no original merge commit was +. specified). Use -c <commit> to reword the commit message. These lines can be re-ordered; they are executed from top to bottom. " | git stripspace --comment-lines >>"$todo" @@ -900,6 +906,8 @@ fi if test t != "$preserve_merges" then git rebase--helper --make-script ${keep_empty:+--keep-empty} \ + ${recreate_merges:+--recreate-merges} \ + ${rebase_cousins:+--rebase-cousins} \ $revisions ${restrict_revision+^$restrict_revision} >"$todo" || die "$(gettext "Could not generate todo list")" else diff --git a/git-rebase.sh b/git-rebase.sh index b353c33d417..9487e543bec 100755 --- a/git-rebase.sh +++ b/git-rebase.sh @@ -17,6 +17,7 @@ q,quiet! be quiet. implies --no-stat autostash automatically stash/stash pop before and after fork-point use 'merge-base --fork-point' to refine upstream onto=! rebase onto given branch instead of upstream +recreate-merges? try to recreate merges instead of skipping them p,preserve-merges! try to recreate merges instead of ignoring them s,strategy=! use the given merge strategy no-ff! cherry-pick all commits, even if unchanged @@ -87,6 +88,8 @@ type= state_dir= # One of {'', continue, skip, abort}, as parsed from command line action= +recreate_merges= +rebase_cousins= preserve_merges= autosquash= keep_empty= @@ -267,6 +270,19 @@ do --allow-empty-message) allow_empty_message=--allow-empty-message ;; + --recreate-merges) + recreate_merges=t + test -z "$interactive_rebase" && interactive_rebase=implied + ;; + --recreate-merges=*) + recreate_merges=t + case "${1#*=}" in + rebase-cousins) rebase_cousins=t;; + no-rebase-cousins) rebase_cousins=;; + *) die "Unknown mode: $1";; + esac + test -z "$interactive_rebase" && interactive_rebase=implied + ;; --preserve-merges) preserve_merges=t test -z "$interactive_rebase" && interactive_rebase=implied diff --git a/refs.c b/refs.c index 20ba82b4343..e8b84c189ff 100644 --- a/refs.c +++ b/refs.c @@ -600,7 +600,8 @@ int dwim_log(const char *str, int len, struct object_id *oid, char **log) static int is_per_worktree_ref(const char *refname) { return !strcmp(refname, "HEAD") || - starts_with(refname, "refs/bisect/"); + starts_with(refname, "refs/bisect/") || + starts_with(refname, "refs/rewritten/"); } static int is_pseudoref_syntax(const char *refname) diff --git a/sequencer.c b/sequencer.c index cfa01d3bdd2..b2bf63029d4 100644 --- a/sequencer.c +++ b/sequencer.c @@ -23,6 +23,10 @@ #include "hashmap.h" #include "notes-utils.h" #include "sigchain.h" +#include "unpack-trees.h" +#include "worktree.h" +#include "oidmap.h" +#include "oidset.h" #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION" @@ -120,6 +124,13 @@ static GIT_PATH_FUNC(rebase_path_stopped_sha, "rebase-merge/stopped-sha") static GIT_PATH_FUNC(rebase_path_rewritten_list, "rebase-merge/rewritten-list") static GIT_PATH_FUNC(rebase_path_rewritten_pending, "rebase-merge/rewritten-pending") + +/* + * The path of the file listing refs that need to be deleted after the rebase + * finishes. This is used by the `label` command to record the need for cleanup. + */ +static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete") + /* * The following files are written by git-rebase just after parsing the * command-line (and are only consumed, not modified, by the sequencer). @@ -244,18 +255,33 @@ static const char *gpg_sign_opt_quoted(struct replay_opts *opts) int sequencer_remove_state(struct replay_opts *opts) { - struct strbuf dir = STRBUF_INIT; + struct strbuf buf = STRBUF_INIT; int i; + if (strbuf_read_file(&buf, rebase_path_refs_to_delete(), 0) > 0) { + char *p = buf.buf; + while (*p) { + char *eol = strchr(p, '\n'); + if (eol) + *eol = '\0'; + if (delete_ref("(rebase -i) cleanup", p, NULL, 0) < 0) + warning(_("could not delete '%s'"), p); + if (!eol) + break; + p = eol + 1; + } + } + free(opts->gpg_sign); free(opts->strategy); for (i = 0; i < opts->xopts_nr; i++) free(opts->xopts[i]); free(opts->xopts); - strbuf_addstr(&dir, get_dir(opts)); - remove_dir_recursively(&dir, 0); - strbuf_release(&dir); + strbuf_reset(&buf); + strbuf_addstr(&buf, get_dir(opts)); + remove_dir_recursively(&buf, 0); + strbuf_release(&buf); return 0; } @@ -1280,6 +1306,10 @@ enum todo_command { TODO_SQUASH, /* commands that do something else than handling a single commit */ TODO_EXEC, + TODO_LABEL, + TODO_RESET, + TODO_MERGE, + TODO_MERGE_AND_EDIT, /* commands that do nothing but are counted for reporting progress */ TODO_NOOP, TODO_DROP, @@ -1298,6 +1328,10 @@ static struct { { 'f', "fixup" }, { 's', "squash" }, { 'x', "exec" }, + { 'l', "label" }, + { 't', "reset" }, + { 'm', "merge" }, + { 0, "merge" }, /* MERGE_AND_EDIT */ { 0, "noop" }, { 'd', "drop" }, { 0, NULL } @@ -1803,13 +1837,29 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol) return error(_("missing arguments for %s"), command_to_string(item->command)); - if (item->command == TODO_EXEC) { + if (item->command == TODO_EXEC || item->command == TODO_LABEL || + item->command == TODO_RESET) { item->commit = NULL; item->arg = bol; item->arg_len = (int)(eol - bol); return 0; } + if (item->command == TODO_MERGE) { + if (skip_prefix(bol, "-C", &bol)) + bol += strspn(bol, " \t"); + else if (skip_prefix(bol, "-c", &bol)) { + bol += strspn(bol, " \t"); + item->command = TODO_MERGE_AND_EDIT; + } else { + item->command = TODO_MERGE_AND_EDIT; + item->commit = NULL; + item->arg = bol; + item->arg_len = (int)(eol - bol); + return 0; + } + } + end_of_object_name = (char *) bol + strcspn(bol, " \t\n"); saved = *end_of_object_name; *end_of_object_name = '\0'; @@ -2444,6 +2494,304 @@ static int do_exec(const char *command_line) return status; } +static int safe_append(const char *filename, const char *fmt, ...) +{ + va_list ap; + struct lock_file lock = LOCK_INIT; + int fd = hold_lock_file_for_update(&lock, filename, + LOCK_REPORT_ON_ERROR); + struct strbuf buf = STRBUF_INIT; + + if (fd < 0) + return -1; + + if (strbuf_read_file(&buf, filename, 0) < 0 && errno != ENOENT) + return error_errno(_("could not read '%s'"), filename); + strbuf_complete(&buf, '\n'); + va_start(ap, fmt); + strbuf_vaddf(&buf, fmt, ap); + va_end(ap); + + if (write_in_full(fd, buf.buf, buf.len) < 0) { + error_errno(_("could not write to '%s'"), filename); + strbuf_release(&buf); + rollback_lock_file(&lock); + return -1; + } + if (commit_lock_file(&lock) < 0) { + strbuf_release(&buf); + rollback_lock_file(&lock); + return error(_("failed to finalize '%s'"), filename); + } + + strbuf_release(&buf); + return 0; +} + +static int do_label(const char *name, int len) +{ + struct ref_store *refs = get_main_ref_store(); + struct ref_transaction *transaction; + struct strbuf ref_name = STRBUF_INIT, err = STRBUF_INIT; + struct strbuf msg = STRBUF_INIT; + int ret = 0; + struct object_id head_oid; + + if (len == 1 && *name == '#') + return error("Illegal label name: '%.*s'", len, name); + + strbuf_addf(&ref_name, "refs/rewritten/%.*s", len, name); + strbuf_addf(&msg, "rebase -i (label) '%.*s'", len, name); + + transaction = ref_store_transaction_begin(refs, &err); + if (!transaction) { + error("%s", err.buf); + ret = -1; + } else if (get_oid("HEAD", &head_oid)) { + error(_("could not read HEAD")); + ret = -1; + } else if (ref_transaction_update(transaction, ref_name.buf, &head_oid, + NULL, 0, msg.buf, &err) < 0 || + ref_transaction_commit(transaction, &err)) { + error("%s", err.buf); + ret = -1; + } + ref_transaction_free(transaction); + strbuf_release(&err); + strbuf_release(&msg); + + if (!ret) + ret = safe_append(rebase_path_refs_to_delete(), + "%s\n", ref_name.buf); + strbuf_release(&ref_name); + + return ret; +} + +static int do_reset(const char *name, int len, struct replay_opts *opts) +{ + struct strbuf ref_name = STRBUF_INIT; + struct object_id oid; + struct lock_file lock = LOCK_INIT; + struct tree_desc desc; + struct tree *tree; + struct unpack_trees_options unpack_tree_opts; + int ret = 0, i; + + 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; + } + + memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts)); + unpack_tree_opts.head_idx = 1; + unpack_tree_opts.src_index = &the_index; + unpack_tree_opts.dst_index = &the_index; + unpack_tree_opts.fn = oneway_merge; + unpack_tree_opts.merge = 1; + unpack_tree_opts.update = 1; + unpack_tree_opts.reset = 1; + + if (read_cache_unmerged()) { + rollback_lock_file(&lock); + strbuf_release(&ref_name); + return error_resolve_conflict(_(action_name(opts))); + } + + if (!fill_tree_descriptor(&desc, &oid)) { + error(_("failed to find tree of %s"), oid_to_hex(&oid)); + rollback_lock_file(&lock); + free((void *)desc.buffer); + strbuf_release(&ref_name); + return -1; + } + + if (unpack_trees(1, &desc, &unpack_tree_opts)) { + rollback_lock_file(&lock); + free((void *)desc.buffer); + strbuf_release(&ref_name); + return -1; + } + + tree = parse_tree_indirect(&oid); + prime_cache_tree(&the_index, tree); + + if (write_locked_index(&the_index, &lock, COMMIT_LOCK) < 0) + ret = error(_("could not write index")); + free((void *)desc.buffer); + + if (!ret) { + struct strbuf msg = STRBUF_INIT; + + strbuf_addf(&msg, "(rebase -i) reset '%.*s'", len, name); + ret = update_ref(msg.buf, "HEAD", &oid, NULL, 0, + UPDATE_REFS_MSG_ON_ERR); + strbuf_release(&msg); + } + + strbuf_release(&ref_name); + return ret; +} + +static int do_merge(struct commit *commit, const char *arg, int arg_len, + int run_commit_flags, struct replay_opts *opts) +{ + int merge_arg_len; + struct strbuf ref_name = STRBUF_INIT; + struct commit *head_commit, *merge_commit, *i; + struct commit_list *common, *j, *reversed = NULL; + struct merge_options o; + int can_fast_forward, ret; + static struct lock_file lock; + + for (merge_arg_len = 0; merge_arg_len < arg_len; merge_arg_len++) + if (isspace(arg[merge_arg_len])) + break; + + if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) + return -1; + + head_commit = lookup_commit_reference_by_name("HEAD"); + if (!head_commit) { + rollback_lock_file(&lock); + return error(_("cannot merge without a current revision")); + } + + if (commit) { + const char *message = get_commit_buffer(commit, NULL); + const char *body; + int len; + + if (!message) { + rollback_lock_file(&lock); + return error(_("could not get commit message of '%s'"), + oid_to_hex(&commit->object.oid)); + } + write_author_script(message); + find_commit_subject(message, &body); + len = strlen(body); + if (write_message(body, len, git_path_merge_msg(), 0) < 0) { + error_errno(_("could not write '%s'"), + git_path_merge_msg()); + unuse_commit_buffer(commit, message); + rollback_lock_file(&lock); + return -1; + } + unuse_commit_buffer(commit, message); + } else { + const char *p = arg + merge_arg_len; + struct strbuf buf = STRBUF_INIT; + int len; + + strbuf_addf(&buf, "author %s", git_author_info(0)); + write_author_script(buf.buf); + strbuf_reset(&buf); + + p += strspn(p, " \t"); + if (*p == '#' && isspace(p[1])) + p += 1 + strspn(p + 1, " \t"); + if (*p) + len = strlen(p); + else { + strbuf_addf(&buf, "Merge branch '%.*s'", + merge_arg_len, arg); + p = buf.buf; + len = buf.len; + } + + if (write_message(p, len, git_path_merge_msg(), 0) < 0) { + error_errno(_("could not write '%s'"), + git_path_merge_msg()); + strbuf_release(&buf); + rollback_lock_file(&lock); + return -1; + } + strbuf_release(&buf); + } + + /* + * If HEAD is not identical to the parent of the original merge commit, + * we cannot fast-forward. + */ + can_fast_forward = opts->allow_ff && commit && commit->parents && + !oidcmp(&commit->parents->item->object.oid, + &head_commit->object.oid); + + strbuf_addf(&ref_name, "refs/rewritten/%.*s", merge_arg_len, arg); + merge_commit = lookup_commit_reference_by_name(ref_name.buf); + if (!merge_commit) { + /* fall back to non-rewritten ref or commit */ + strbuf_splice(&ref_name, 0, strlen("refs/rewritten/"), "", 0); + merge_commit = lookup_commit_reference_by_name(ref_name.buf); + } + if (!merge_commit) { + error(_("could not resolve '%s'"), ref_name.buf); + strbuf_release(&ref_name); + rollback_lock_file(&lock); + return -1; + } + + if (can_fast_forward && commit->parents->next && + !commit->parents->next->next && + !oidcmp(&commit->parents->next->item->object.oid, + &merge_commit->object.oid)) { + strbuf_release(&ref_name); + rollback_lock_file(&lock); + return fast_forward_to(&commit->object.oid, + &head_commit->object.oid, 0, opts); + } + + write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ, + git_path_merge_head(), 0); + write_message("no-ff", 5, git_path_merge_mode(), 0); + + common = get_merge_bases(head_commit, merge_commit); + for (j = common; j; j = j->next) + commit_list_insert(j->item, &reversed); + free_commit_list(common); + + read_cache(); + init_merge_options(&o); + o.branch1 = "HEAD"; + o.branch2 = ref_name.buf; + o.buffer_output = 2; + + ret = merge_recursive(&o, head_commit, merge_commit, reversed, &i); + if (ret <= 0) + fputs(o.obuf.buf, stdout); + strbuf_release(&o.obuf); + if (ret < 0) { + strbuf_release(&ref_name); + rollback_lock_file(&lock); + return error(_("conflicts while merging '%.*s'"), + merge_arg_len, arg); + } + + if (active_cache_changed && + write_locked_index(&the_index, &lock, COMMIT_LOCK)) { + strbuf_release(&ref_name); + return error(_("merge: Unable to write new index file")); + } + rollback_lock_file(&lock); + + ret = run_git_commit(git_path_merge_msg(), opts, run_commit_flags); + strbuf_release(&ref_name); + + return ret; +} + static int is_final_fixup(struct todo_list *todo_list) { int i = todo_list->current; @@ -2627,6 +2975,18 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts) /* `current` will be incremented below */ todo_list->current = -1; } + } else if (item->command == TODO_LABEL) + res = do_label(item->arg, item->arg_len); + else if (item->command == TODO_RESET) + res = do_reset(item->arg, item->arg_len, opts); + else if (item->command == TODO_MERGE || + item->command == TODO_MERGE_AND_EDIT) { + res = do_merge(item->commit, item->arg, item->arg_len, + item->command == TODO_MERGE_AND_EDIT ? + EDIT_MSG | VERIFY_MSG : 0, opts); + if (item->commit) + record_in_rewritten(&item->commit->object.oid, + peek_command(todo_list, 1)); } else if (!is_noop(item->command)) return error(_("unknown command %d"), item->command); @@ -2981,6 +3341,345 @@ void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag) strbuf_release(&sob); } +struct labels_entry { + struct hashmap_entry entry; + char label[FLEX_ARRAY]; +}; + +static int labels_cmp(const void *fndata, const struct labels_entry *a, + const struct labels_entry *b, const void *key) +{ + return key ? strcmp(a->label, key) : strcmp(a->label, b->label); +} + +struct string_entry { + struct oidmap_entry entry; + char string[FLEX_ARRAY]; +}; + +struct label_state { + struct oidmap commit2label; + struct hashmap labels; + struct strbuf buf; +}; + +static const char *label_oid(struct object_id *oid, const char *label, + struct label_state *state) +{ + struct labels_entry *labels_entry; + struct string_entry *string_entry; + struct object_id dummy; + size_t len; + int i; + + string_entry = oidmap_get(&state->commit2label, oid); + if (string_entry) + return string_entry->string; + + /* + * For "uninteresting" commits, i.e. commits that are not to be + * rebased, and which can therefore not be labeled, we use a unique + * abbreviation of the commit name. This is slightly more complicated + * than calling find_unique_abbrev() because we also need to make + * sure that the abbreviation does not conflict with any other + * label. + * + * We disallow "interesting" commits to be labeled by a string that + * is a valid full-length hash, to ensure that we always can find an + * abbreviation for any uninteresting commit's names that does not + * clash with any other label. + */ + if (!label) { + char *p; + + strbuf_reset(&state->buf); + strbuf_grow(&state->buf, GIT_SHA1_HEXSZ); + label = p = state->buf.buf; + + find_unique_abbrev_r(p, oid->hash, default_abbrev); + + /* + * We may need to extend the abbreviated hash so that there is + * no conflicting label. + */ + if (hashmap_get_from_hash(&state->labels, strihash(p), p)) { + size_t i = strlen(p) + 1; + + oid_to_hex_r(p, oid); + for (; i < GIT_SHA1_HEXSZ; i++) { + char save = p[i]; + p[i] = '\0'; + if (!hashmap_get_from_hash(&state->labels, + strihash(p), p)) + break; + p[i] = save; + } + } + } else if (((len = strlen(label)) == GIT_SHA1_RAWSZ && + !get_oid_hex(label, &dummy)) || + (len == 1 && *label == '#') || + hashmap_get_from_hash(&state->labels, + strihash(label), label)) { + /* + * If the label already exists, or if the label is a valid full + * OID, or the label is a '#' (which we use as a separator + * between merge heads and oneline), we append a dash and a + * number to make it unique. + */ + struct strbuf *buf = &state->buf; + + strbuf_reset(buf); + strbuf_add(buf, label, len); + + for (i = 2; ; i++) { + strbuf_setlen(buf, len); + strbuf_addf(buf, "-%d", i); + if (!hashmap_get_from_hash(&state->labels, + strihash(buf->buf), + buf->buf)) + break; + } + + label = buf->buf; + } + + FLEX_ALLOC_STR(labels_entry, label, label); + hashmap_entry_init(labels_entry, strihash(label)); + hashmap_add(&state->labels, labels_entry); + + FLEX_ALLOC_STR(string_entry, string, label); + oidcpy(&string_entry->entry.oid, oid); + oidmap_put(&state->commit2label, string_entry); + + return string_entry->string; +} + +static int make_script_with_merges(struct pretty_print_context *pp, + struct rev_info *revs, FILE *out, + unsigned flags) +{ + int keep_empty = flags & TODO_LIST_KEEP_EMPTY; + int rebase_cousins = flags & TODO_LIST_REBASE_COUSINS; + struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT; + struct strbuf label = STRBUF_INIT; + struct commit_list *commits = NULL, **tail = &commits, *iter; + struct commit_list *tips = NULL, **tips_tail = &tips; + struct commit *commit; + struct oidmap commit2todo = OIDMAP_INIT; + struct string_entry *entry; + struct oidset interesting = OIDSET_INIT, child_seen = OIDSET_INIT, + shown = OIDSET_INIT; + struct label_state state = { OIDMAP_INIT, { NULL }, STRBUF_INIT }; + + int abbr = flags & TODO_LIST_ABBREVIATE_CMDS; + const char *cmd_pick = abbr ? "p" : "pick", + *cmd_label = abbr ? "l" : "label", + *cmd_reset = abbr ? "t" : "reset", + *cmd_merge = abbr ? "m" : "merge"; + + oidmap_init(&commit2todo, 0); + oidmap_init(&state.commit2label, 0); + hashmap_init(&state.labels, (hashmap_cmp_fn) labels_cmp, NULL, 0); + strbuf_init(&state.buf, 32); + + if (revs->cmdline.nr && (revs->cmdline.rev[0].flags & BOTTOM)) { + struct object_id *oid = &revs->cmdline.rev[0].item->oid; + FLEX_ALLOC_STR(entry, string, "onto"); + oidcpy(&entry->entry.oid, oid); + oidmap_put(&state.commit2label, entry); + } + + /* + * First phase: + * - get onelines for all commits + * - gather all branch tips (i.e. 2nd or later parents of merges) + * - label all branch tips + */ + while ((commit = get_revision(revs))) { + struct commit_list *to_merge; + int is_octopus; + const char *p1, *p2; + struct object_id *oid; + + tail = &commit_list_insert(commit, tail)->next; + oidset_insert(&interesting, &commit->object.oid); + + if ((commit->object.flags & PATCHSAME)) + continue; + + strbuf_reset(&oneline); + pretty_print_commit(pp, commit, &oneline); + + to_merge = commit->parents ? commit->parents->next : NULL; + if (!to_merge) { + /* non-merge commit: easy case */ + strbuf_reset(&buf); + if (!keep_empty && is_original_commit_empty(commit)) + strbuf_addf(&buf, "%c ", comment_line_char); + strbuf_addf(&buf, "%s %s %s", cmd_pick, + oid_to_hex(&commit->object.oid), + oneline.buf); + + FLEX_ALLOC_STR(entry, string, buf.buf); + oidcpy(&entry->entry.oid, &commit->object.oid); + oidmap_put(&commit2todo, entry); + + continue; + } + + is_octopus = to_merge && to_merge->next; + + if (is_octopus) + BUG("Octopus merges not yet supported"); + + /* Create a label */ + strbuf_reset(&label); + if (skip_prefix(oneline.buf, "Merge ", &p1) && + (p1 = strchr(p1, '\'')) && + (p2 = strchr(++p1, '\''))) + strbuf_add(&label, p1, p2 - p1); + else if (skip_prefix(oneline.buf, "Merge pull request ", + &p1) && + (p1 = strstr(p1, " from "))) + strbuf_addstr(&label, p1 + strlen(" from ")); + else + strbuf_addbuf(&label, &oneline); + + for (p1 = label.buf; *p1; p1++) + if (isspace(*p1)) + *(char *)p1 = '-'; + + strbuf_reset(&buf); + strbuf_addf(&buf, "%s -C %s", + cmd_merge, oid_to_hex(&commit->object.oid)); + + /* label the tip of merged branch */ + oid = &to_merge->item->object.oid; + strbuf_addch(&buf, ' '); + + if (!oidset_contains(&interesting, oid)) + strbuf_addstr(&buf, label_oid(oid, NULL, &state)); + else { + tips_tail = &commit_list_insert(to_merge->item, + tips_tail)->next; + + strbuf_addstr(&buf, label_oid(oid, label.buf, &state)); + } + strbuf_addf(&buf, " # %s", oneline.buf); + + FLEX_ALLOC_STR(entry, string, buf.buf); + oidcpy(&entry->entry.oid, &commit->object.oid); + oidmap_put(&commit2todo, entry); + } + + /* + * Second phase: + * - label branch points + * - add HEAD to the branch tips + */ + for (iter = commits; iter; iter = iter->next) { + struct commit_list *parent = iter->item->parents; + for (; parent; parent = parent->next) { + struct object_id *oid = &parent->item->object.oid; + if (!oidset_contains(&interesting, oid)) + continue; + if (!oidset_contains(&child_seen, oid)) + oidset_insert(&child_seen, oid); + else + label_oid(oid, "branch-point", &state); + } + + /* Add HEAD as implict "tip of branch" */ + if (!iter->next) + tips_tail = &commit_list_insert(iter->item, + tips_tail)->next; + } + + /* + * Third phase: output the todo list. This is a bit tricky, as we + * want to avoid jumping back and forth between revisions. To + * accomplish that goal, we walk backwards from the branch tips, + * gathering commits not yet shown, reversing the list on the fly, + * then outputting that list (labeling revisions as needed). + */ + fprintf(out, "%s onto\n", cmd_label); + for (iter = tips; iter; iter = iter->next) { + struct commit_list *list = NULL, *iter2; + + commit = iter->item; + if (oidset_contains(&shown, &commit->object.oid)) + continue; + entry = oidmap_get(&state.commit2label, &commit->object.oid); + + if (entry) + fprintf(out, "\n# Branch %s\n", entry->string); + else + fprintf(out, "\n"); + + while (oidset_contains(&interesting, &commit->object.oid) && + !oidset_contains(&shown, &commit->object.oid)) { + commit_list_insert(commit, &list); + if (!commit->parents) { + commit = NULL; + break; + } + commit = commit->parents->item; + } + + if (!commit) + fprintf(out, "%s onto\n", cmd_reset); + else { + const char *to = NULL; + + entry = oidmap_get(&state.commit2label, + &commit->object.oid); + if (entry) + to = entry->string; + else if (!rebase_cousins) + to = label_oid(&commit->object.oid, NULL, + &state); + + if (!to || !strcmp(to, "onto")) + fprintf(out, "%s onto\n", cmd_reset); + else { + strbuf_reset(&oneline); + pretty_print_commit(pp, commit, &oneline); + fprintf(out, "%s %s # %s\n", + cmd_reset, to, oneline.buf); + } + } + + for (iter2 = list; iter2; iter2 = iter2->next) { + struct object_id *oid = &iter2->item->object.oid; + entry = oidmap_get(&commit2todo, oid); + /* only show if not already upstream */ + if (entry) + fprintf(out, "%s\n", entry->string); + entry = oidmap_get(&state.commit2label, oid); + if (entry) + fprintf(out, "%s %s\n", + cmd_label, entry->string); + oidset_insert(&shown, oid); + } + + free_commit_list(list); + } + + free_commit_list(commits); + free_commit_list(tips); + + strbuf_release(&label); + strbuf_release(&oneline); + strbuf_release(&buf); + + oidmap_free(&commit2todo, 1); + oidmap_free(&state.commit2label, 1); + hashmap_free(&state.labels, 1); + strbuf_release(&state.buf); + + return 0; +} + int sequencer_make_script(FILE *out, int argc, const char **argv, unsigned flags) { @@ -2991,11 +3690,16 @@ int sequencer_make_script(FILE *out, int argc, const char **argv, struct commit *commit; int keep_empty = flags & TODO_LIST_KEEP_EMPTY; const char *insn = flags & TODO_LIST_ABBREVIATE_CMDS ? "p" : "pick"; + int recreate_merges = flags & TODO_LIST_RECREATE_MERGES; init_revisions(&revs, NULL); revs.verbose_header = 1; - revs.max_parents = 1; - revs.cherry_pick = 1; + if (recreate_merges) + revs.cherry_mark = 1; + else { + revs.max_parents = 1; + revs.cherry_pick = 1; + } revs.limited = 1; revs.reverse = 1; revs.right_only = 1; @@ -3019,6 +3723,9 @@ int sequencer_make_script(FILE *out, int argc, const char **argv, if (prepare_revision_walk(&revs) < 0) return error(_("make_script: error preparing revisions")); + if (recreate_merges) + return make_script_with_merges(&pp, &revs, out, flags); + while ((commit = get_revision(&revs))) { strbuf_reset(&buf); if (!keep_empty && is_original_commit_empty(commit)) @@ -3108,8 +3815,14 @@ int transform_todos(unsigned flags) short_commit_name(item->commit) : oid_to_hex(&item->commit->object.oid); + if (item->command == TODO_MERGE) + strbuf_addstr(&buf, " -C"); + else if (item->command == TODO_MERGE_AND_EDIT) + strbuf_addstr(&buf, " -c"); + strbuf_addf(&buf, " %s", oid); } + /* add all the rest */ if (!item->arg_len) strbuf_addch(&buf, '\n'); diff --git a/sequencer.h b/sequencer.h index e45b178dfc4..739dd0fa92b 100644 --- a/sequencer.h +++ b/sequencer.h @@ -59,6 +59,13 @@ int sequencer_remove_state(struct replay_opts *opts); #define TODO_LIST_KEEP_EMPTY (1U << 0) #define TODO_LIST_SHORTEN_IDS (1U << 1) #define TODO_LIST_ABBREVIATE_CMDS (1U << 2) +#define TODO_LIST_RECREATE_MERGES (1U << 3) +/* + * When recreating merges, commits that do have the base commit as ancestor + * ("cousins") are *not* rebased onto the new base by default. If those + * commits should be rebased onto the new base, this flag needs to be passed. + */ +#define TODO_LIST_REBASE_COUSINS (1U << 4) int sequencer_make_script(FILE *out, int argc, const char **argv, unsigned flags); diff --git a/t/t3430-rebase-recreate-merges.sh b/t/t3430-rebase-recreate-merges.sh new file mode 100755 index 00000000000..9a59f12b670 --- /dev/null +++ b/t/t3430-rebase-recreate-merges.sh @@ -0,0 +1,208 @@ +#!/bin/sh +# +# Copyright (c) 2017 Johannes E. Schindelin +# + +test_description='git rebase -i --recreate-merges + +This test runs git rebase "interactively", retaining the branch structure by +recreating merge commits. + +Initial setup: + + -- B -- (first) + / \ + A - C - D - E - H (master) + \ / + F - G (second) +' +. ./test-lib.sh +. "$TEST_DIRECTORY"/lib-rebase.sh + +test_expect_success 'setup' ' + write_script replace-editor.sh <<-\EOF && + mv "$1" "$(git rev-parse --git-path ORIGINAL-TODO)" + cp script-from-scratch "$1" + EOF + + test_commit A && + git checkout -b first && + test_commit B && + git checkout master && + test_commit C && + test_commit D && + git merge --no-commit B && + test_tick && + git commit -m E && + git tag -m E E && + git checkout -b second C && + test_commit F && + test_commit G && + git checkout master && + git merge --no-commit G && + test_tick && + git commit -m H && + git tag -m H H +' + +cat >script-from-scratch <<\EOF +label onto + +# onebranch +pick G +pick D +label onebranch + +# second +reset onto +pick B +label second + +reset onto +merge -C H second +merge onebranch # Merge the topic branch 'onebranch' +EOF + +test_cmp_graph () { + cat >expect && + git log --graph --boundary --format=%s "$@" >output && + sed "s/ *$//" <output >output.trimmed && + test_cmp expect output.trimmed +} + +test_expect_success 'create completely different structure' ' + test_config sequence.editor \""$PWD"/replace-editor.sh\" && + test_tick && + git rebase -i --recreate-merges A && + test_cmp_graph <<-\EOF + * Merge the topic branch '\''onebranch'\'' + |\ + | * D + | * G + * | H + |\ \ + | |/ + |/| + | * B + |/ + * A + EOF +' + +test_expect_success 'generate correct todo list' ' + cat >expect <<-\EOF && + label onto + + reset onto + pick d9df450 B + label E + + reset onto + pick 5dee784 C + label branch-point + pick ca2c861 F + pick 088b00a G + label H + + reset branch-point # C + pick 12bd07b D + merge -C 2051b56 E # E + merge -C 233d48a H # H + + EOF + + grep -v "^#" <.git/ORIGINAL-TODO >output && + test_cmp expect output +' + +test_expect_success 'with a branch tip that was cherry-picked already' ' + git checkout -b already-upstream master && + base="$(git rev-parse --verify HEAD)" && + + test_commit A1 && + test_commit A2 && + git reset --hard $base && + test_commit B1 && + test_tick && + git merge -m "Merge branch A" A2 && + + git checkout -b upstream-with-a2 $base && + test_tick && + git cherry-pick A2 && + + git checkout already-upstream && + test_tick && + git rebase -i --recreate-merges upstream-with-a2 && + test_cmp_graph upstream-with-a2.. <<-\EOF + * Merge branch A + |\ + | * A1 + * | B1 + |/ + o A2 + EOF +' + +test_expect_success 'do not rebase cousins unless asked for' ' + write_script copy-editor.sh <<-\EOF && + cp "$1" "$(git rev-parse --git-path ORIGINAL-TODO)" + EOF + + test_config sequence.editor \""$PWD"/copy-editor.sh\" && + git checkout -b cousins master && + before="$(git rev-parse --verify HEAD)" && + test_tick && + git rebase -i --recreate-merges HEAD^ && + test_cmp_rev HEAD $before && + test_tick && + git rebase -i --recreate-merges=rebase-cousins HEAD^ && + test_cmp_graph HEAD^.. <<-\EOF + * Merge the topic branch '\''onebranch'\'' + |\ + | * D + | * G + |/ + o H + EOF +' + +test_expect_success 'refs/rewritten/* is worktree-local' ' + git worktree add wt && + cat >wt/script-from-scratch <<-\EOF && + label xyz + exec GIT_DIR=../.git git rev-parse --verify refs/rewritten/xyz >a || : + exec git rev-parse --verify refs/rewritten/xyz >b + EOF + + test_config -C wt sequence.editor \""$PWD"/replace-editor.sh\" && + git -C wt rebase -i HEAD && + test_must_be_empty wt/a && + test_cmp_rev HEAD "$(cat wt/b)" +' + +test_expect_success 'post-rewrite hook and fixups work for merges' ' + git checkout -b post-rewrite && + test_commit same1 && + git reset --hard HEAD^ && + test_commit same2 && + git merge -m "to fix up" same1 && + echo same old same old >same2.t && + test_tick && + git commit --fixup HEAD same2.t && + fixup="$(git rev-parse HEAD)" && + + mkdir -p .git/hooks && + test_when_finished "rm .git/hooks/post-rewrite" && + echo "cat >actual" | write_script .git/hooks/post-rewrite && + + test_tick && + git rebase -i --autosquash --recreate-merges HEAD^^^ && + printf "%s %s\n%s %s\n%s %s\n%s %s\n" >expect $(git rev-parse \ + $fixup^^2 HEAD^2 \ + $fixup^^ HEAD^ \ + $fixup^ HEAD \ + $fixup HEAD) && + test_cmp expect actual +' + +test_done -- 2.16.1.windows.4