From: Phillip Wood Date: Fri, 15 Jul 2022 15:37:34 GMT Subject: Re: [PATCH v4 03/12] branch: consider refs under 'update-refs' Message-ID: <8e533a1d-9d8f-a09f-e036-37ba39023aee@gmail.com> In-Reply-To: On 12/07/2022 14:06, Derrick Stolee via GitGitGadget wrote: > From: Derrick Stolee > > The branch_checked_out() helper helps commands like 'git branch' and > 'git fetch' from overwriting refs that are currently checked out in > other worktrees. > > A future update to 'git rebase' will introduce a new '--update-refs' > option which will update the local refs that point to commits that are > being rebased. To avoid collisions as the rebase completes, we want to > make the future data store for these refs to be considered by > branch_checked_out(). > > The data store is a plaintext file inside the 'rebase-merge' directory > for that worktree. The file lists refnames followed by two OIDs, each on > separate lines. The OIDs will be used to store the original values of > the refs and the to-be-written values as the rebase progresses, but can > be ignored at the moment. > > Create a new sequencer_get_update_refs_state() method that parses this > file and populates a struct string_list with the ref-OID pairs. We can > then use this list to add to the current_checked_out_branches strmap > used by branch_checked_out(). > > To properly navigate to the rebase directory for a given worktree, > extract the static strbuf_worktree_gitdir() method to a public API > method. > > We can test that this works without having Git write this file by > artificially creating one in our test script, at least until 'git rebase > --update-refs' is implemented and we can use it directly. This looks good, I've left a couple of comments below but I'm not sure they're even worth reading let alone replying to! Best Wishes Phillip > Signed-off-by: Derrick Stolee > --- > branch.c | 13 +++++++ > sequencer.c | 74 +++++++++++++++++++++++++++++++++++++++ > sequencer.h | 9 +++++ > t/t2407-worktree-heads.sh | 23 ++++++++++++ > 4 files changed, 119 insertions(+) > > diff --git a/branch.c b/branch.c > index 526e8237673..f252c4eef6c 100644 > --- a/branch.c > +++ b/branch.c > @@ -365,6 +365,7 @@ static void prepare_checked_out_branches(void) > char *old; > struct wt_status_state state = { 0 }; > struct worktree *wt = worktrees[i++]; > + struct string_list update_refs = STRING_LIST_INIT_DUP; > > if (wt->is_bare) > continue; > @@ -400,6 +401,18 @@ static void prepare_checked_out_branches(void) > strbuf_release(&ref); > } > wt_status_state_free_buffers(&state); > + > + if (!sequencer_get_update_refs_state(get_worktree_git_dir(wt), > + &update_refs)) { > + struct string_list_item *item; > + for_each_string_list_item(item, &update_refs) { > + old = strmap_put(¤t_checked_out_branches, > + item->string, > + xstrdup(wt->path)); > + free(old); > + } > + string_list_clear(&update_refs, 1); > + } > } > > free_worktrees(worktrees); > diff --git a/sequencer.c b/sequencer.c > index 8c3ed3532ac..e93c61cbd25 100644 > --- a/sequencer.c > +++ b/sequencer.c > @@ -147,6 +147,20 @@ static GIT_PATH_FUNC(rebase_path_squash_onto, "rebase-merge/squash-onto") > */ > static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete") > > +/* > + * The update-refs file stores a list of refs that will be updated at the end > + * of the rebase sequence. The 'update-ref ' commands in the todo file > + * update the OIDs for the refs in this file, but the refs are not updated > + * until the end of the rebase sequence. > + * > + * rebase_path_update_refs() returns the path to this file for a given > + * worktree directory. For the current worktree, pass the_repository->gitdir. > + */ > +static char *rebase_path_update_refs(const char *wt_dir) It is nice to see this function. The naming of wt_dir confused me slightly, wt_git_dir would make it clear that this function takes the git_dir of the worktree and not the worktree directory. Theu documentation does a good job of clarifying that though. > +{ > + return xstrfmt("%s/rebase-merge/update-refs", wt_dir); > +} > + > /* > * The following files are written by git-rebase just after parsing the > * command-line. > @@ -169,6 +183,15 @@ static GIT_PATH_FUNC(rebase_path_no_reschedule_failed_exec, "rebase-merge/no-res > static GIT_PATH_FUNC(rebase_path_drop_redundant_commits, "rebase-merge/drop_redundant_commits") > static GIT_PATH_FUNC(rebase_path_keep_redundant_commits, "rebase-merge/keep_redundant_commits") > > +/** > + * A 'struct update_refs_record' represents a value in the update-refs > + * list. We use a string_list to map refs to these (before, after) pairs. > + */ > +struct update_ref_record { > + struct object_id before; > + struct object_id after; > +}; > + > static int git_sequencer_config(const char *k, const char *v, void *cb) > { > struct replay_opts *opts = cb; > @@ -5901,3 +5924,54 @@ int sequencer_determine_whence(struct repository *r, enum commit_whence *whence) > > return 0; > } > + > +int sequencer_get_update_refs_state(const char *wt_dir, > + struct string_list *refs) > +{ > + int result = 0; > + FILE *fp = NULL; > + struct strbuf ref = STRBUF_INIT; > + struct strbuf hash = STRBUF_INIT; > + struct update_ref_record *rec = NULL; > + > + char *path = rebase_path_update_refs(wt_dir); > + > + fp = fopen(path, "r"); > + if (!fp) > + goto cleanup; > + > + while (strbuf_getline(&ref, fp) != EOF) { > + struct string_list_item *item; > + > + CALLOC_ARRAY(rec, 1); It does not matter but later in the series we use rec = xmalloc(sizeof(*rec)) to do this. I'm not sure the project has a standard way of allocating a single instance of something. > + > + if (strbuf_getline(&hash, fp) == EOF || > + get_oid_hex(hash.buf, &rec->before)) { > + warning(_("update-refs file at '%s' is invalid"), > + path); > + result = -1; > + goto cleanup; > + } > + > + if (strbuf_getline(&hash, fp) == EOF || > + get_oid_hex(hash.buf, &rec->after)) { > + warning(_("update-refs file at '%s' is invalid"), > + path); > + result = -1; > + goto cleanup; > + } > + > + item = string_list_insert(refs, ref.buf); > + item->util = rec; > + rec = NULL; > + } > + > +cleanup: > + if (fp) > + fclose(fp); > + free(path); > + free(rec); > + strbuf_release(&ref); > + strbuf_release(&hash); > + return result; > +} > diff --git a/sequencer.h b/sequencer.h > index da64473636b..3ae541bb145 100644 > --- a/sequencer.h > +++ b/sequencer.h > @@ -232,4 +232,13 @@ void sequencer_post_commit_cleanup(struct repository *r, int verbose); > int sequencer_get_last_command(struct repository* r, > enum replay_action *action); > int sequencer_determine_whence(struct repository *r, enum commit_whence *whence); > + > +/** > + * Append the set of ref-OID pairs that are currently stored for the 'git > + * rebase --update-refs' feature if such a rebase is currently happening. > + * > + * Localized to a worktree's git dir. > + */ > +int sequencer_get_update_refs_state(const char *wt_dir, struct string_list *refs); > + > #endif /* SEQUENCER_H */ > diff --git a/t/t2407-worktree-heads.sh b/t/t2407-worktree-heads.sh > index a67ce5fb003..97f5c87f8c8 100755 > --- a/t/t2407-worktree-heads.sh > +++ b/t/t2407-worktree-heads.sh > @@ -81,6 +81,29 @@ test_expect_success !SANITIZE_LEAK 'refuse to overwrite: worktree in rebase (mer > grep "cannot force update the branch '\''wt-2'\'' checked out at.*wt-2" err > ' > > +test_expect_success 'refuse to overwrite: worktree in rebase with --update-refs' ' > + test_when_finished rm -rf .git/worktrees/wt-3/rebase-merge && > + > + mkdir -p .git/worktrees/wt-3/rebase-merge && > + touch .git/worktrees/wt-3/rebase-merge/interactive && > + > + cat >.git/worktrees/wt-3/rebase-merge/update-refs <<-EOF && > + refs/heads/fake-3 > + $(git rev-parse HEAD~1) > + $(git rev-parse HEAD) > + refs/heads/fake-4 > + $(git rev-parse HEAD) > + $(git rev-parse HEAD) > + EOF > + > + for i in 3 4 > + do > + test_must_fail git branch -f fake-$i HEAD 2>err && > + grep "cannot force update the branch '\''fake-$i'\'' checked out at.*wt-3" err || > + return 1 > + done > +' > + > test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: checked out' ' > test_must_fail git fetch server +refs/heads/wt-3:refs/heads/wt-3 2>err && > grep "refusing to fetch into branch '\''refs/heads/wt-3'\''" err &&