From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Nieder Subject: Re: [PATCH 11/17] revert: Save data for continuing after conflict resolution Date: Tue, 12 Jul 2011 14:37:16 -0500 Message-ID: <20110712193716.GB14909@elie> References: <1310396048-24925-1-git-send-email-artagnon@gmail.com> <1310396048-24925-12-git-send-email-artagnon@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Git List , Junio C Hamano , Christian Couder , Daniel Barkalow To: Ramkumar Ramachandra X-From: git-owner@vger.kernel.org Tue Jul 12 21:37:32 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Qgilv-0001Cp-Ey for gcvg-git-2@lo.gmane.org; Tue, 12 Jul 2011 21:37:32 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754896Ab1GLTh1 (ORCPT ); Tue, 12 Jul 2011 15:37:27 -0400 Received: from mail-vx0-f174.google.com ([209.85.220.174]:37184 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754872Ab1GLTh0 (ORCPT ); Tue, 12 Jul 2011 15:37:26 -0400 Received: by vxb39 with SMTP id 39so3691054vxb.19 for ; Tue, 12 Jul 2011 12:37:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=weiMpAVYrY46fbAkgQY0a5xHpsqVzFmG4977lgWqGKY=; b=ufbLtMYe+HnkQy7UARJ9dLcQZrO3AnJ5V6eioFbH8vdUuj1n1dhm0N13GY8OAtrTGB RUKKH6AqOKUyJ4kSxkSjCyG8wGhYMDwlkmPtMP4yT8eRTxjMypMPpxGvrZ/xEYDEOWOV YsEapY6SJ8TybpUNE+vE2yya86KAePEo8aPlU= Received: by 10.52.176.10 with SMTP id ce10mr384991vdc.280.1310499445356; Tue, 12 Jul 2011 12:37:25 -0700 (PDT) Received: from elie ([69.209.70.6]) by mx.google.com with ESMTPS id ck16sm5138922vdb.32.2011.07.12.12.37.22 (version=SSLv3 cipher=OTHER); Tue, 12 Jul 2011 12:37:24 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1310396048-24925-12-git-send-email-artagnon@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Hi, Ramkumar Ramachandra wrote: > It is imperative to note that these two files alone are not enough to > implement "--continue"; we will also need to persist the options that > were specified on the command-line, and this is done later in the > series. I think you could remove the phrase "It is imperative to note that" and this would say the same thing. :) By the way, those two files are enough to implement --continue in some sense, no? One implementation of --continue would forget options passed on the first run and require the user to specify them again; it would just be less useful. The reminder that "head" and "todo" are not the only files in the .git/sequencer dir is useful, though; thanks for it. > --- a/builtin/revert.c > +++ b/builtin/revert.c [...] > +static void format_todo(struct strbuf *buf, struct commit_list *todo_list, > + struct replay_opts *opts) > +{ > + struct commit_list *cur = NULL; > + struct commit_message msg = { NULL, NULL, NULL, NULL, NULL }; > + const char *sha1_abbrev = NULL; > + const char *action; > + > + action = (opts->action == REVERT ? "revert" : "pick"); > + for (cur = todo_list; cur; cur = cur->next) { > + sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV); > + if (get_message(cur->item, &msg)) > + die(_("Cannot get commit message for %s"), sha1_abbrev); > + strbuf_addf(buf, "%s %s %s\n", action, sha1_abbrev, msg.subject); This die() seems odd in the context of a series that starts by converting various die() calls to "return error()". > +static struct commit *parse_insn_line(char *start, struct replay_opts *opts) > +{ > + unsigned char commit_sha1[20]; > + char sha1_abbrev[40]; > + struct commit *commit; > + enum replay_action action; > + int insn_len = 0; > + char *p; > + > + p = start; > + if (!(p = strchr(p, ' '))) > + return NULL; Style: it is much, much clearer to write p = strchr(start, ' '); if (!p) return NULL; In the git codebase, assignments in "if" conditionals are very rare, so code like the above sticks out. > + insn_len = p - start; > + if (!(p = strchr(p + 1, ' '))) > + return NULL; > + p += 1; Likewise. This could say: insn_len = p - start; p = strchr(p + 1, ' '); if (!p) return NULL; p++; or: p = strchrnul(start, ' '); if (!*p) return error("no commit name in todo file line: %s", start); p++; q = strchrnul(p, ' '); if (q - p > sizeof(sha1_abbrev) - 1) return error("commit name in todo file is too long: %s", start); *mempcpy(sha1_abbrev, p, q - p) = '\0'; > + if (!strncmp(start, "pick", insn_len)) > + action = CHERRY_PICK; > + else if (!strncmp(start, "revert", insn_len)) > + action = REVERT; This code means that "p", "pi", and "pic" are accepted as abbreviations for "pick". Maybe a comment would help to clarify that. Are we okay with reserving these names, so "r" in a todo file means to "revert" and not to "reword" like it does in a rebase -i todo list? > + /* > + * Verify that the action matches up with the one in > + * opts; we don't support arbitrary instructions > + */ > + if (action != opts->action) > + return NULL; If I try "git cherry-pick foo..bar" and then "git revert --continue", what error message will I get? > +static void read_populate_todo(struct commit_list **todo_list, > + struct replay_opts *opts) > +{ [...] > + for (p = buf.buf; *p; p = strchr(p, '\n') + 1) { > + if (!(commit = parse_insn_line(p, opts))) > + goto error; > + new = xmalloc(sizeof(struct commit_list)); > + new->item = commit; > + *next = new; > + next = &new->next; commit_list_append()? > +static void create_seq_dir(void) > +{ > + if (file_exists(git_path(SEQ_DIR))) { > + if (!is_directory(git_path(SEQ_DIR)) && remove_path(git_path(SEQ_DIR)) < 0) > + die(_("Could not remove %s"), git_path(SEQ_DIR)); > + } else if (mkdir(git_path(SEQ_DIR), 0777) < 0) > + die_errno(_("Could not create sequencer directory '%s'."), git_path(SEQ_DIR)); > +} As mentioned in [1], a local would make this more readable. And it's not clear to me why one would want to delete a .git/sequencer file that the user carefully placed there (I don't think git itself ever writes such a thing). > + > +static void save_head(const char *head) > +{ > + static struct lock_file head_lock; > + struct strbuf buf = STRBUF_INIT; > + int fd; > + > + fd = hold_lock_file_for_update(&head_lock, git_path(SEQ_HEAD_FILE), LOCK_DIE_ON_ERROR); > + strbuf_addf(&buf, "%s\n", head); > + if (write_in_full(fd, buf.buf, buf.len) < 0) > + die_errno(_("Could not write to %s."), git_path(SEQ_HEAD_FILE)); > + if (commit_lock_file(&head_lock) < 0) > + die(_("Error wrapping up %s"), git_path(SEQ_HEAD_FILE)); > +} A local would be helpful here, too. > +static void save_todo(struct commit_list *todo_list, struct replay_opts *opts) > +{ > + static struct lock_file todo_lock; > + struct strbuf buf = STRBUF_INIT; > + int fd; > + > + fd = hold_lock_file_for_update(&todo_lock, git_path(SEQ_TODO_FILE), LOCK_DIE_ON_ERROR); > + format_todo(&buf, todo_list, opts); > + if (write_in_full(fd, buf.buf, buf.len) < 0) { > + strbuf_release(&buf); > + die_errno(_("Could not write to %s."), git_path(SEQ_TODO_FILE)); > + } > + if (commit_lock_file(&todo_lock) < 0) { > + strbuf_release(&buf); > + die(_("Error wrapping up %s"), git_path(SEQ_TODO_FILE)); > + } > + strbuf_release(&buf); > +} Likewise here. As mentioned before, git_path() clobbers errno, so the above is likely to print a wrong error message on some systems (e.g., "fatal: Cannot write to .git/sequencer/todo: Success"). > + > +static int pick_commits(struct replay_opts *opts) > +{ > + struct commit_list *todo_list = NULL; > + unsigned char sha1[20]; > + struct commit_list *cur; > + int res; > > setenv(GIT_REFLOG_ACTION, me, 0); > if (opts->allow_ff) > @@ -580,14 +764,24 @@ static int pick_commits(struct replay_opts *opts) > opts->record_origin || opts->edit)); > read_and_refresh_cache(me, opts); > > - prepare_revs(&revs, opts); > + walk_revs_populate_todo(&todo_list, opts); > + create_seq_dir(); > + if (!get_sha1("HEAD", sha1)) > + save_head(sha1_to_hex(sha1)); What happens if the .git/sequencer dir already exists (e.g., we were in the middle of a multiple-cherry-pick)? What happens if I try to cherry-pick onto an unborn branch, or get_sha1() fails for some other reason? Regards, Jonathan [1] http://thread.gmane.org/gmane.comp.version-control.git/176647/focus=176675